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  • 1.
    Afshar, Reza
    et al.
    Uppsala universitet, Teknisk-naturvetenskapliga vetenskapsområdet, Tekniska sektionen, Institutionen för teknikvetenskaper, Tillämpad mekanik.
    Alavyoon, Navid
    Uppsala universitet, Teknisk-naturvetenskapliga vetenskapsområdet, Tekniska sektionen, Institutionen för teknikvetenskaper, Mikrosystemteknik.
    Ahlgren, Anders
    Swedish National Maritime Museums, the Vasa Museum.
    van Dijk, Nico P.
    Uppsala universitet, Teknisk-naturvetenskapliga vetenskapsområdet, Tekniska sektionen, Institutionen för teknikvetenskaper, Tillämpad mekanik.
    Vorobyev, Alexey
    Uppsala universitet, Teknisk-naturvetenskapliga vetenskapsområdet, Tekniska sektionen, Institutionen för teknikvetenskaper, Tillämpad mekanik.
    Gamstedt, Kristofer
    Uppsala universitet, Teknisk-naturvetenskapliga vetenskapsområdet, Tekniska sektionen, Institutionen för teknikvetenskaper, Tillämpad mekanik.
    A full-scale finite-element model of the Vasa ship2017Ingår i: Proceedings of ECCOMAS Thematic Conference CompWood 2017: Computational Methods in Wood Mechanics, 2017Konferensbidrag (Refereegranskat)
    Abstract [en]

    A full-scale model of the 17th century Vasa shipwreck has been developed to assess its current and future structural stability as well as design an improved support structure. A wireframe model, consisting of only lines, points and curves to describe the geometry of the ship, has been provided by the Vasa museum. It has been developed based on geodetic measurements using a total station. From this wireframe model, a three-dimensional (3D) model comprising solid bodies for solid-like parts (i.e. hull and keel), surfaces for the shell-like components (deck planks) and lines for beam-like constituents (deck beams) has been developed in Creo Parametric 3D software. This geometric model has been imported in finite-element software, Ansys, for further development of the stiffeners (knees, riders, stanchions, masts, etc.), adjustment of the correct location of deck beams and, finally, structural analyses of the entire ship (Figure 1). The procedure for selection of the different types of elements in the finite-element (FE) model, the definition of orthotropic material properties for the timber structure and preliminary results are discussed in this paper. Experiences drawn from this engineering project may also be useful in development of finite element models for structural assessment of other complex wooden structures in cultural heritage.

  • 2.
    Ahlberg, Patrik
    et al.
    Uppsala universitet, Teknisk-naturvetenskapliga vetenskapsområdet, Tekniska sektionen, Institutionen för teknikvetenskaper, Fasta tillståndets elektronik.
    Seung, Hee Jeong
    Uppsala universitet, Teknisk-naturvetenskapliga vetenskapsområdet, Tekniska sektionen, Institutionen för teknikvetenskaper, Fasta tillståndets elektronik.
    Jiao, Mingzhi
    Uppsala universitet, Teknisk-naturvetenskapliga vetenskapsområdet, Tekniska sektionen, Institutionen för teknikvetenskaper, Mikrosystemteknik.
    Wu, Zhigang
    Uppsala universitet, Teknisk-naturvetenskapliga vetenskapsområdet, Tekniska sektionen, Institutionen för teknikvetenskaper, Mikrosystemteknik.
    Zhang, Shi-Li
    Uppsala universitet, Teknisk-naturvetenskapliga vetenskapsområdet, Tekniska sektionen, Institutionen för teknikvetenskaper, Fasta tillståndets elektronik.
    Zhang, Zhi-Bin
    Uppsala universitet, Teknisk-naturvetenskapliga vetenskapsområdet, Tekniska sektionen, Institutionen för teknikvetenskaper, Fasta tillståndets elektronik.
    Graphene as a Diffusion Barrier in Galinstan-Solid Metal Contacts2014Ingår i: IEEE Transactions on Electron Devices, ISSN 0018-9383, E-ISSN 1557-9646, Vol. 61, nr 8, s. 2996-3000Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    This paper presents the use of graphene as a diffusion barrier to a eutectic Ga-In-Sn alloy, i.e., galinstan, for electrical contacts in electronics. Galinstan is known to be incompatible with many conventional metals used for electrical contacts. When galinstan is in direct contact with Al thin films, Al is readily dissolved leading to the formation of Al oxides present on the surface of the galinstan droplets. This reaction is monitored ex situ using several material analysis methods as well as in situ using a simple circuit to follow the time-dependent resistance variation. In the presence of a multilayer graphene diffusion barrier, the Al-galinstan reaction is effectively prevented for galinstan deposited by means of drop casting. When deposited by spray coating, the high-impact momentum of the galinstan droplets causes damage to the multilayer graphene and the Al-galinstan reaction is observed at some defective spots. Nonetheless, the graphene barrier is likely to block the formation of Al oxides at the Al/galinstan interface leading to a stable electrical current in the test circuit.

  • 3.
    Ahmadi, Mohammad
    et al.
    Uppsala universitet, Teknisk-naturvetenskapliga vetenskapsområdet, Tekniska sektionen, Institutionen för teknikvetenskaper, Mikrosystemteknik.
    Wirell, Vilhelm
    Uppsala universitet, Teknisk-naturvetenskapliga vetenskapsområdet, Tekniska sektionen, Institutionen för teknikvetenskaper, Mikrosystemteknik.
    Bullerskärmar i betong: En teknisk studie om gröna bullerskärmar i betong2019Självständigt arbete på grundnivå (yrkesexamen), 10 poäng / 15 hpStudentuppsats (Examensarbete)
    Abstract [en]

    As cities grow and densify, the amount of traffic in and through settlement also increases. Horizontal surfaces are increasingly disappearing in favor of housing and infrastructure. This leads to increased noise levels and increased emissions in both residential and green belts.

    Where exploitation cannot be adapted in any other way, or where natural shielding against noise cannot be achieved, noise screens are often erected to minimize noise propagation from roads and railways. The most commonly occurring noise screen today consists of wood, but given its prerequisites, the study intends to investigate whether noise screens in concrete can be a better alternative.

    The purpose is thus to design and dimension noise screens in concrete. The study is carried out in collaboration with Butong AB, which since 2009 has developed and constructed plant walls in concrete.

    The objective is to construct and dimension a self-supporting noise shield, with integrated substrate for plants to grow and germinate, based on Butong's existing plant walls. To achieve the report's objectives, different types of matrices and designs have been evaluated with respect to strength and mechanical properties. The calculations made are numerical and performed in SolidWorks.

    The results from the numerical tests have been used to produce a noise shield with intended dimensions and where loads have been applied according to current eurocodes and SIS standards.

    The conclusion indicates that green noise screens in concrete maintain a high competitiveness against noise screens in wood. The long span, good mechanical properties and aesthetically pleasing design are some of the factors that support the conclusion.

  • 4. Ali, M.
    et al.
    Svensk, O.
    Zhen, Z.
    Suihkonen, S.
    Törmä, P. T.
    Lipsanen, H.
    Sopanen, M.
    Hjort, Klas
    Uppsala universitet, Teknisk-naturvetenskapliga vetenskapsområdet, Tekniska sektionen, Institutionen för teknikvetenskaper, Mikrosystemteknik.
    Jensen, Jens
    Uppsala universitet, Teknisk-naturvetenskapliga vetenskapsområdet, Tekniska sektionen, Institutionen för teknikvetenskaper, Jonfysik.
    Reduced photoluminescence from InGaN/GaN multiple quantum well structures following 40 MeV iodine ion irradiation2009Ingår i: Physica. B, Condensed matter, ISSN 0921-4526, E-ISSN 1873-2135, Vol. 404, nr 23-24, s. 4925-4928Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    The effects following ion irradiation of GaN-based devices are still limited. Here we present data on the photoluminescence (PL) emitted from InGaN/GaN multiple quantum well (MQW) structures, which have been exposed to 40 MeV lion irradiation. The PL is reduced as a function of applied ion fluence, with essentially no PL signal left above 10(11) ions/cm(2). It is observed that even the ion fluences in the 10(9) ions/cm(2) range have a pronounced effect on the photoluminescence properties of the MQW structures. This may have consequences concerning application of InGaN/GaN MQW's in radiation-rich environments, in addition to defect build-up during ion beam analysis.

  • 5.
    An, Hongbin
    et al.
    Huazhong Univ Sci & Technol, State Key Lab Digital Mfg Equipment & Technol, Wuhan 430074, Hubei, Peoples R China.
    Chen, Liangzhou
    Huazhong Univ Sci & Technol, State Key Lab Digital Mfg Equipment & Technol, Wuhan 430074, Hubei, Peoples R China.
    Liu, Xiaojun
    Huazhong Univ Sci & Technol, State Key Lab Digital Mfg Equipment & Technol, Wuhan 430074, Hubei, Peoples R China.
    Zhao, Bin
    Huazhong Univ Sci & Technol, State Key Lab Digital Mfg Equipment & Technol, Wuhan 430074, Hubei, Peoples R China.
    Ma, Donglin
    Huazhong Univ Sci & Technol, Sch Opt & Elect Informat, Wuhan 430074, Hubei, Peoples R China.
    Wu, Zhigang
    Uppsala universitet, Teknisk-naturvetenskapliga vetenskapsområdet, Tekniska sektionen, Institutionen för teknikvetenskaper, Mikrosystemteknik. Huazhong Univ Sci & Technol, State Key Lab Digital Mfg Equipment & Technol, Wuhan 430074, Hubei, Peoples R China.
    A method of manufacturing microfluidic contact lenses by using irreversible bonding and thermoforming2018Ingår i: Journal of Micromechanics and Microengineering, ISSN 0960-1317, E-ISSN 1361-6439, Vol. 28, nr 10, artikel-id 105008Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    In this paper, we present the development of microfluidic contact lenses, which is based on the advantages of wearable microfluidics and can have great potential in the ophthalmology healthcare field. The development consists of two parts; the manufacturing process and the usability tests of the devices. In the manufacturing process, we firstly extended silane coupling and surface modification to irreversibly bond plastic membranes with microchannel-molded silicone rubber, to form the plastic-PDMS plane assemblies, and then molded the plane into a contact lens by thermoforming. We systematically investigated the effects of thermoforming factors, heating temperatures and the terrace die's sphere radius on channels by using the factorial experiment design. In addition, various tests were conducted to verify the usability of the devices. Through blockage and leakage tests, the devices were proved to be feasible, with no channel-blockages and could stand high pressures. Through a wearing test, the contact lenses were confirmed to be harmless on the living body. Furthermore, by performing the manipulating test, the device was proved to be liquid-controllable. These works provide a foundation for the applications of microfluidic contact lenses in ophthalmology.

  • 6.
    An, Hongbin
    et al.
    HUST, Sch Mech Sci & Engn, Wuhan 430074, Hubei, Peoples R China.
    Chen, Liangzhou
    HUST, Sch Mech Sci & Engn, Wuhan 430074, Hubei, Peoples R China.
    Liu, Xiaojun
    HUST, Sch Mech Sci & Engn, Wuhan 430074, Hubei, Peoples R China.
    Zhao, Bin
    HUST, Sch Mech Sci & Engn, Wuhan 430074, Hubei, Peoples R China.
    Zhang, Hong
    HUST, Tongji Med Coll, Tongji Hosp, Dept Ophthalmol, Wuhan 430074, Hubei, Peoples R China.
    Wu, Zhigang
    Uppsala universitet, Teknisk-naturvetenskapliga vetenskapsområdet, Tekniska sektionen, Institutionen för teknikvetenskaper, Mikrosystemteknik. HUST, Sch Mech Sci & Engn, Wuhan 430074, Hubei, Peoples R China.
    Microfluidic contact lenses for unpowered, continuous and non-invasive intraocular pressure monitoring2019Ingår i: Sensors and Actuators A-Physical, ISSN 0924-4247, E-ISSN 1873-3069, Vol. 295, s. 177-187Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    Intraocular pressure (IOP) is a crucial physiological indicator of the visual system and play a key role in the diagnosis and treatment of glaucoma. However, the current handheld single measurement tools for IOP sensing cannot meet the future demands for glaucoma management. Thus, here we present the microfluidic contact lens sensors that could provide unpowered, continuous and non-invasive IOP monitoring. The microfluidic contact lens is comprised of a sensing layer of the micropatterned soft-elastomer and a hard plastic reference layer. The devices use the annular sensing chamber filled with the dyed liquid and a sensing microchannel as the IOP transducer. Resulting from the volume variance of the sensing chamber and caused by the deformation of the sensing layer under pressure, the IOP signal is detected as the displacement change of the dyed liquid's interface in the sensing channel, and in which, the displacement change can be optically observed by using the smart-phone camera. Based on the silicone rubber model eyeball, the sensing mechanism of the devices with different design parameters (the position of the sensing chambers and the dimension of the sensing channels) are explored by using the theoretical analyses and experimental investigations. The characteristics of these microfluidic contact lens sensors are tested, in which, the maximum sensitivity of the device (with the sensing chamber of 8.5 mm in diameter and the sensing channel of 100 x 40 um in size) can be achieved to 0.708 mm/mmHg in a working range of 0 (4) over tilde0 mmHg. Also, cyclical tests were conducted and indicated that the devices had a good reversibility and Long-term stability. Furthermore, the device (with the sensing chamber of 5.0 mm in diameter and the sensing channel of 150 x 40 urn in size) was test on the porcine eyes ex vivo, showing a sensitivity of 0.2832 mm/mmHg in a range of 8 (3) over tilde2 mmHg and, the device had a good reproducibility to its IOP change. This work provides a promising approach for unpowered, continuous and non-invasive monitoring of IOP.

  • 7.
    Andersson, Marlene
    et al.
    Department of Anatomy, Physiology and Biochemistry, Swedish University of Agricultural Sciences, Uppsala, Sweden..
    Jia, Qiupin
    Institute of Biological Sciences and Biotechnology, Donghua University, Shanghai, P.R. China..
    Abella, Ana
    ETSI de Caminos and Center for Biomedical Technology, Universidad Politécnica de Madrid, Madrid, Spain..
    Lee, Xiau-Yeen
    ETSI de Caminos and Center for Biomedical Technology, Universidad Politécnica de Madrid, Madrid, Spain..
    Landreh, Michael
    Department of Chemistry, Physical and Theoretical Chemistry Laboratory, University of Oxford, Oxford, UK..
    Purhonen, Pasi
    Department of Biosciences and Nutrition, Karolinska Institutet, Stockholm, Sweden.; School of Technology and Health, KTH Royal Institute of Technology, Stockholm, Sweden..
    Hebert, Hans
    Department of Biosciences and Nutrition, Karolinska Institutet, Stockholm, Sweden.; School of Technology and Health, KTH Royal Institute of Technology, Stockholm, Sweden..
    Tenje, Maria
    Uppsala universitet, Teknisk-naturvetenskapliga vetenskapsområdet, Tekniska sektionen, Institutionen för teknikvetenskaper, Mikrosystemteknik. Uppsala universitet, Science for Life Laboratory, SciLifeLab. Department of Biomedical Engineering, Lund University, Lund, Sweden..
    Robinson, Carol V.
    Department of Chemistry, Physical and Theoretical Chemistry Laboratory, University of Oxford, Oxford, UK..
    Meng, Qing
    Institute of Biological Sciences and Biotechnology, Donghua University, Shanghai, P.R. China..
    Plaza, Gustavo R.
    ETSI de Caminos and Center for Biomedical Technology, Universidad Politécnica de Madrid, Madrid, Spain..
    Johansson, Jan
    Department of Anatomy, Physiology and Biochemistry, Swedish University of Agricultural Sciences, Uppsala, Sweden.; Department of Neurobiology, Care Sciences and Society (NVS), Karolinska Institutet, Stockholm, Sweden.; Karolinska Institutet.
    Rising, Anna
    Department of Anatomy, Physiology and Biochemistry, Swedish University of Agricultural Sciences, Uppsala, Sweden.;Department of Neurobiology, Care Sciences and Society (NVS), Karolinska Institutet, Stockholm, Sweden.; Karolinska Institutet.
    Biomimetic spinning of artificial spider silk from a chimeric minispidroin2017Ingår i: Nature Chemical Biology, ISSN 1552-4450, E-ISSN 1552-4469, Vol. 13, nr 3, s. 262-264Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    Herein we present a chimeric recombinant spider silk protein (spidroin) whose aqueous solubility equals that of native spider silk dope and a spinning device that is based solely on aqueous buffers, shear forces and lowered pH. The process recapitulates the complex molecular mechanisms that dictate native spider silk spinning and is highly efficient; spidroin from one liter of bacterial shake-flask culture is enough to spin a kilometer of the hitherto toughest as-spun artificial spider silk fiber.

  • 8.
    Andersson, Martin
    Uppsala universitet, Teknisk-naturvetenskapliga vetenskapsområdet, Tekniska sektionen, Institutionen för teknikvetenskaper, Mikrosystemteknik.
    Ag-In transient liquid phase bonding for high temperature stainless steel micro actuators2013Självständigt arbete på avancerad nivå (yrkesexamen), 20 poäng / 30 hpStudentuppsats (Examensarbete)
    Abstract [en]

    A stainless steel, high temperature, phase change micro actuator has been demonstrated using the solid-liquid phase transition of mannitol at 168°C and In-Ag transient liquid phase diffusion bonding. Joints created with this bonding technique can sustain temperatures up to 695°C, while being bonded at only 180°C, and have thicknesses between 1.4 to 6.0 μm. Physical vapour deposition, inkjet printing and electroplating have been evaluated as deposition methods for bond layers. For actuation, cavities were filled with mannitol and when heated, the expansion was used to deflect a 10 μm thick stainless steel membrane. Bond strengths of the joints are found to be in the region of 0.51 to 2.53 MPa and pressurised cavities sustained pressures of up to 30 bar. Bond strength is limited by the bond contact area and the surface roughness of the bonding layers.

  • 9.
    Andersson, Martin
    Uppsala universitet, Teknisk-naturvetenskapliga vetenskapsområdet, Tekniska sektionen, Institutionen för teknikvetenskaper, Mikrosystemteknik.
    Microfluidics at High Pressures: Understanding, Sensing, and Control2018Doktorsavhandling, sammanläggning (Övrigt vetenskapligt)
    Abstract [en]

    This thesis explores understanding, sensing, and control in high-pressure microfluidics. The high-pressure regime allows fluids to be forced through narrow channels at substantial speed and creates conditions for fluids of high density and low viscosity—features desired in flow-based chemical analyses. With changes to pressure and temperature, fluid properties vary, and for miniaturized flow systems, sensing and control are needed.

    For miniaturized chemical analytics to utilize high-pressure fluids, like supercritical CO2, sensors are required for flow characterization. In this thesis, high-pressure tolerant sensors in glass chips have been developed and investigated. By the use of chip-integrated temperature, flow, and relative permittivity sensors, the variable behavior of supercritical CO2 or binary component CO2-alcohol mixtures have been investigated. To be able to change flow rates, a heat-based actuator chip has been developed. By a flow control system, which combines a relative permittivity sensor and heat actuated flow regulators on a modular system, the composition of binary component CO2-alcohol mixtures can be tuned and controlled with feedback.

    Flows of multiphase CO2-H2O hold promise for miniaturized extraction systems. In this thesis, parallel multiphase CO2-H2O flow has been studied. To achieve control, methods have been investigated where channels have been modified by the introduction of a guiding ridge and altered by a chemical coating. Flow is a dynamic process, where pressure and temperature can vary with time and place. As the properties of fluids containing CO2 may change with pressure and temperature, properties will also change with time and place. Because of this, instruments with spatial and temporal resolution are needed to better understand dynamic chemical effects at flow. In this thesis, a tool is presented to study the dynamic acidification of aqueous solutions that come in contact with flowing CO2.

    By a study performed to understand the strength and pressure tolerance of glass chips, it has been found that the fracture is not only determined by the applied pressure, but also on time and environment.

    Delarbeten
    1. Fracture strength of glass chips for high-pressure microfluidics
    Öppna denna publikation i ny flik eller fönster >>Fracture strength of glass chips for high-pressure microfluidics
    2016 (Engelska)Ingår i: Journal of Micromechanics and Microengineering, ISSN 0960-1317, E-ISSN 1361-6439, Vol. 26, nr 9, artikel-id 095009Artikel i tidskrift (Refereegranskat) Published
    Abstract [en]

    High-pressure microfluidics exposes new areas in chemistry. In this paper, the reliability of transparent borosilicate glass chips is investigated. Two designs of circular cavities are used for fracture strength tests, either 1.6 mm wide with rounded corners to the fluid inlets, or 2.0 mm wide with sharp inlet corners. Two kinds of tests are done, either short-term,e.g. pressurization to fracture at room temperature, or long-term, with fracture at constant pressurization for up to one week, in the temperature region 11–125 °C. The speed of crack fronts is measured using a high-speed camera. Results show fracture stresses in the range of 129 and 254 MPa for short-term measurements. Long-term measurements conclude the presences of a temperature and stress dependent delayed fracture. For a reliability ofone week at 11–38 °C, a pressure limit is found at the lower end of the short-term measurements, or 15% lower than the average. At 80 °C, this pressure limit is 45% lower. Crack speeds are measured to be 10−5 m s-1 during short-term fracture. These measurements are comparable with estimations based on slow crack growth and show that the growth affects the reliability of glass chips. This effect is strongly affected by high temperatures, thus lowers the operating window of high-pressure glass microfluidic devices.

    Nyckelord
    glass, fracture strength, high pressure microfluidics, crack growth, temperature dependence
    Nationell ämneskategori
    Övrig annan teknik
    Forskningsämne
    Teknisk fysik med inriktning mot mikrosystemteknik
    Identifikatorer
    urn:nbn:se:uu:diva-309983 (URN)10.1088/0960-1317/26/9/095009 (DOI)000402408400009 ()
    Forskningsfinansiär
    Vetenskapsrådet, 2011:5037Knut och Alice Wallenbergs Stiftelse
    Tillgänglig från: 2016-12-08 Skapad: 2016-12-08 Senast uppdaterad: 2018-06-19Bibliografiskt granskad
    2. Influence of flow rate, temperature and pressure on multiphase flows of supercritical carbon dioxide and water using multivariate partial least square regression
    Öppna denna publikation i ny flik eller fönster >>Influence of flow rate, temperature and pressure on multiphase flows of supercritical carbon dioxide and water using multivariate partial least square regression
    Visa övriga...
    2015 (Engelska)Ingår i: Journal of Micromechanics and Microengineering, ISSN 0960-1317, E-ISSN 1361-6439, Vol. 25, nr 10, artikel-id 105001Artikel i tidskrift (Refereegranskat) Published
    Abstract [en]

    Supercritical carbon dioxide (scCO2) is often used to replace harmful solvents and can dissolve a wide range of organic compounds. With a favorable critical point at 31 °C and 7.4 MPa, reaching above the critical point for scCO2 is fairly accessible. Because of the compressible nature of scCO2 and the large changes of viscosity and density with temperature and pressure, there is a need to determine the behavior of scCO2 in microfluidic systems. Here, the influence of how parameters such as flow rate, temperature, pressure, and flow ratio affects the length of parallel flow of water and scCO2 and the length of the created CO2 segments are investigated and modeled using multivariate data analysis for a 10 mm long double-y channel. The parallel length and segment size were observed in the laminar regime around and above the critical point of CO2. The flow ratio between the two fluids together with the flow rate influenced both the parallel length and the segment sizes, and a higher pressure resulted in shorter parallel lengths. Regarding the segment length of CO2, longer segments were a result of a higher Weber number for H2O together with a higher temperature in the channel. 

    Nyckelord
    Supercritical fluids, microfluidics, carbon dioxide, partial least square regression, principal component analysis, fluid dynamics, multiphase flow
    Nationell ämneskategori
    Teknik och teknologier Annan materialteknik
    Identifikatorer
    urn:nbn:se:uu:diva-253552 (URN)10.1088/0960-1317/25/10/105001 (DOI)000366827400017 ()
    Forskningsfinansiär
    Vetenskapsrådet, 2011-5037Knut och Alice Wallenbergs Stiftelse
    Tillgänglig från: 2015-05-29 Skapad: 2015-05-29 Senast uppdaterad: 2018-06-19Bibliografiskt granskad
    3. Influence of surface modifications and channel structure for microflows of supercritical carbon dioxide and water
    Öppna denna publikation i ny flik eller fönster >>Influence of surface modifications and channel structure for microflows of supercritical carbon dioxide and water
    2016 (Engelska)Ingår i: Journal of Supercritical Fluids, ISSN 0896-8446, E-ISSN 1872-8162, Vol. 107, s. 649-656Artikel i tidskrift (Refereegranskat) Published
    Abstract [en]

    Miniaturization offers a possibility to increase the performance and decrease the time scales of systems. Existing microsystems using supercritical CO2 mainly utilizes multiphase segmented flows. To allow for a broader toolbox for future systems, also parallel flows are useful which eases the separation of the different phases. Here, the effect of different surface coatings are studied for multiphase flows of scCO2 and H2O in flat microchannels, with and without a 4 μm high ridge guide, which allows for pinning of the fluid interface inside the 190 μm wide and 35 μm high channel. Three different surfaces with different wettings towards scCO2 and H2O are studied, where a surface terminated with a hydrocarbon-based silane was observed to be neutral in the H2O/scCO2 system, a surface terminated with a fluorocarbon-based silane was hydrophobic, and an uncoated glass surface was hydrophilic.

    Using two flow rates of 5:5 μl/min (CO2:H2O) and 6.5:3.5 μl/min (CO2:H2O), a parallel flow between scCO2 and H2O was observed for uncoated and flat channels where the H2O flow pushed the CO2 to the side, before the flows eventually breaks up into segments. With a ridge guide in the middle of the channel, the interface was pinned at half the channel width, although still breaking up into segments. The neutral hydrocarbon-based surface coating with approximately 90° contact angles resulted in evenly created segments without a ridge guide. Including a guide in the middle of the channel, a parallel flow was observed throughout the channel, although occasionally small CO2 segments entered the H2O outlet. Using the fluorocarbon-based silane resulted in an unstable segmented system with pressure fluctuations.

    Using surface modifications, an increased control can be achieved for either segmentation or parallel flow where a neutral surface is favored for a stable flow behavior. Together with a ridge guide, the fluid interface was pinned at the center. 

    Nyckelord
    Microfluidics, Supercritical CO2, Silane coating, Parallel flow, Segmented flow, Surface modification
    Nationell ämneskategori
    Teknik och teknologier Kemiteknik
    Identifikatorer
    urn:nbn:se:uu:diva-253554 (URN)10.1016/j.supflu.2015.07.027 (DOI)000366077100077 ()
    Forskningsfinansiär
    Vetenskapsrådet, 2011-5037Knut och Alice Wallenbergs Stiftelse
    Tillgänglig från: 2015-05-29 Skapad: 2015-05-29 Senast uppdaterad: 2018-06-19Bibliografiskt granskad
    4. Thin film metal sensors in fusion bonded glass chips for high-pressure microfluidics
    Öppna denna publikation i ny flik eller fönster >>Thin film metal sensors in fusion bonded glass chips for high-pressure microfluidics
    Visa övriga...
    2017 (Engelska)Ingår i: Journal of Micromechanics and Microengineering, ISSN 0960-1317, E-ISSN 1361-6439, Vol. 27, nr 1, artikel-id 015018Artikel i tidskrift (Refereegranskat) Published
    Abstract [en]

    High-pressure microfluidics offers fast analyses of thermodynamic parameters for compressed process solvents. However, microfluidic platforms handling highly compressible supercritical CO2 are difficult to control, and on-chip sensing would offer added control of the devices. Therefore, there is a need to integrate sensors into highly pressure tolerant glass chips. In this paper, thin film Pt sensors were embedded in shallow etched trenches in a glass wafer that was bonded with another glass wafer having microfluidic channels. The devices having sensors integrated into the flow channels sustained pressures up to 220 bar, typical for the operation of supercritical CO2. No leakage from the devices could be found. Integrated temperature sensors were capable of measuring local decompression cooling effects and integrated calorimetric sensors measured flow velocities over the range 0.5-13.8 mm/s. By this, a better control of high-pressure microfluidic platforms has been achieved.

    Nyckelord
    supercritical carbon dioxide, high pressure microfluidics, integrated electrodes, temperature sensing, flow sensing, glass
    Nationell ämneskategori
    Övrig annan teknik
    Forskningsämne
    Teknisk fysik med inriktning mot mikrosystemteknik
    Identifikatorer
    urn:nbn:se:uu:diva-310063 (URN)10.1088/0960-1317/27/1/015018 (DOI)000388703300003 ()
    Forskningsfinansiär
    Vetenskapsrådet, 2011-5037VINNOVAKnut och Alice Wallenbergs Stiftelse
    Anmärkning

    Part financed through Swedish Agency for the Innovation System, Vinnova, through the Centre for Natural Disaster Science (CNDS)

    Tillgänglig från: 2016-12-09 Skapad: 2016-12-09 Senast uppdaterad: 2018-06-19Bibliografiskt granskad
    5. A microfluidic relative permittivity sensor for feedback control of carbon dioxide expanded liquid flows
    Öppna denna publikation i ny flik eller fönster >>A microfluidic relative permittivity sensor for feedback control of carbon dioxide expanded liquid flows
    2019 (Engelska)Ingår i: Sensors and Actuators A-Physical, ISSN 0924-4247, E-ISSN 1873-3069, Vol. 285, s. 165-172Artikel i tidskrift (Refereegranskat) Published
    Abstract [en]

    Binary CO2-alcohol mixtures, such as CO2-expanded liquids (CXLs), are promising green solvents for reaching higher performance in flow chemistry and separation processing. However, their compressibility and high working pressure makes handling challenging. These mixtures allow for a tuneable polarity but, to do so, requires precise flow control. Here, a high-pressure tolerant microfluidic system containing a relative permittivity sensor and a mixing chip is used to actively regulate the relative permittivity of these fluids and indirectly—composition. The sensor is a fluid-filled plate capacitor created using embedded 3D-structured thin films and has a linearity of 0.9999, a sensitivity of 4.88 pF per unit of relative permittivity, and a precision within 0.6% for a sampling volume of 0.3 μL. Composition and relative permittivity of CO2-ethanol mixtures were measured at 82 bar and 21 °C during flow. By flow and dielectric models, this relationship was found to be described by the pure components and a quadratic mixing rule with an interaction parameter, kij, of -0.63 ± 0.02. Microflows with a relative permittivity of 1.7–21.4 were generated, and using the models, this was found to correspond to compositions of 6–90 mol % ethanol in CO2. With the sensor, a closed loop control system was realised and CO2-ethanol flows were tuned to setpoints of the relative permittivity in 30 s.

    Nyckelord
    Relative permittivity, Process control, CO2-expanded liquids, Binary fluid mixtures, High-pressure microfluidics
    Nationell ämneskategori
    Kemiteknik Annan elektroteknik och elektronik
    Identifikatorer
    urn:nbn:se:uu:diva-353945 (URN)10.1016/j.sna.2018.11.015 (DOI)000456902600021 ()
    Forskningsfinansiär
    Knut och Alice Wallenbergs Stiftelse
    Tillgänglig från: 2018-06-19 Skapad: 2018-06-19 Senast uppdaterad: 2019-02-25Bibliografiskt granskad
    6. A microfluidic control board for high-pressure flow, composition, and relative permittivity
    Öppna denna publikation i ny flik eller fönster >>A microfluidic control board for high-pressure flow, composition, and relative permittivity
    2018 (Engelska)Ingår i: Analytical Chemistry, ISSN 0003-2700, E-ISSN 1520-6882, Vol. 90, nr 21, s. 12601-12608Artikel i tidskrift (Refereegranskat) Published
    Abstract [en]

    Flow control is central to microfluidics and chromatography. With decreasing dimensions and high pressures, precise fluid flows are often needed. In this paper, a high-pressure flow control system is presented, allowing for the miniaturization of chromatographic systems and the increased performance of microfluidic setups by controlling flow, composition and relative permittivity of two-component flows with CO2. The system consists of four chips: two flow actuator chips, one mixing chip and one relative permittivity sensor. The actuator chips, throttling the flow, required no moving parts as they instead relied on internal heaters to change the fluid resistance. This allows for flow control using miniaturized fluid delivery systems containing only a single pump or pressure source. Mobile phase gradients between 49% to 74% methanol in CO2 were demonstrated. Depending on how the actuator chips were dimensioned, the position of this range could be set for different method-specific needs. With the microfluidic control board, both flow and composition could be controlled from constant pressure sources, drift could be removed, and variations in composition could be lowered by 84%, resulting in microflows of CO2 and methanol with a variation in the composition of 0.30%.

    Nationell ämneskategori
    Kemiteknik
    Identifikatorer
    urn:nbn:se:uu:diva-353953 (URN)10.1021/acs.analchem.8b02758 (DOI)000449722500039 ()30269500 (PubMedID)
    Forskningsfinansiär
    Knut och Alice Wallenbergs Stiftelse
    Tillgänglig från: 2018-06-19 Skapad: 2018-06-19 Senast uppdaterad: 2018-12-21Bibliografiskt granskad
    7. Dynamic pH determination at high pressure of aqueous additive mixtures in contact with dense CO2
    Öppna denna publikation i ny flik eller fönster >>Dynamic pH determination at high pressure of aqueous additive mixtures in contact with dense CO2
    Visa övriga...
    2018 (Engelska)Ingår i: Journal of Supercritical Fluids, ISSN 0896-8446, E-ISSN 1872-8162, Vol. 136, s. 95-101Artikel i tidskrift (Refereegranskat) Published
    Abstract [en]

    A system consisting of a high-pressure tolerant microfluidic glass chip, high-speed absorbance imaging, and image processing has been developed to study rapid dynamic events like pH change in a multiphase flow. The system gives both kinetic and quantitative equilibrated information. By tracking the interactions of aqueous additive mixtures and liquid CO2, at 80 bar and 24 °C, under flow, measurement at a given P, T condition is done in 0.25 s. The acidification rate to steady state was found to be mass transport limited, occurring in less than 1 s. For 30 mM of the additives ammonium acetate and ammonium formate, equilibrium pH of 4.5 and 4.1, respectively, was seen. These additives are of key importance in common mobile phases used in SFC.

    Nyckelord
    Supercritical fluid chromatography, High-pressure microfluidics, Additive salts, Dense CO, Multiphase flow, Image analysis
    Nationell ämneskategori
    Kemiteknik Teknik och teknologier
    Identifikatorer
    urn:nbn:se:uu:diva-353940 (URN)10.1016/j.supflu.2018.02.012 (DOI)000430767400011 ()
    Forskningsfinansiär
    Knut och Alice Wallenbergs Stiftelse
    Tillgänglig från: 2018-06-18 Skapad: 2018-06-18 Senast uppdaterad: 2018-08-02Bibliografiskt granskad
  • 10.
    Andersson, Martin
    et al.
    Uppsala universitet, Teknisk-naturvetenskapliga vetenskapsområdet, Tekniska sektionen, Institutionen för teknikvetenskaper, Mikrosystemteknik.
    Ek, Johan
    Uppsala universitet, Teknisk-naturvetenskapliga vetenskapsområdet, Tekniska sektionen, Institutionen för teknikvetenskaper, Mikrosystemteknik.
    Hedman, Ludvig
    Uppsala universitet, Teknisk-naturvetenskapliga vetenskapsområdet, Tekniska sektionen, Institutionen för teknikvetenskaper, Mikrosystemteknik.
    Johansson, Fredrik
    Uppsala universitet, Teknisk-naturvetenskapliga vetenskapsområdet, Tekniska sektionen, Institutionen för teknikvetenskaper, Mikrosystemteknik.
    Sehlstedt, Viktor
    Uppsala universitet, Teknisk-naturvetenskapliga vetenskapsområdet, Tekniska sektionen, Institutionen för teknikvetenskaper, Mikrosystemteknik.
    Stocklassa, Jesper
    Uppsala universitet, Teknisk-naturvetenskapliga vetenskapsområdet, Tekniska sektionen, Institutionen för teknikvetenskaper, Mikrosystemteknik.
    Snögren, Pär
    Uppsala universitet, Teknisk-naturvetenskapliga vetenskapsområdet, Tekniska sektionen, Institutionen för teknikvetenskaper, Mikrosystemteknik.
    Pettersson, Victor
    Uppsala universitet, Teknisk-naturvetenskapliga vetenskapsområdet, Tekniska sektionen, Institutionen för teknikvetenskaper, Mikrosystemteknik.
    Larsson, Jonas
    Uppsala universitet, Teknisk-naturvetenskapliga vetenskapsområdet, Tekniska sektionen, Institutionen för teknikvetenskaper, Mikrosystemteknik.
    Vizuete, Olivier
    Uppsala universitet, Teknisk-naturvetenskapliga vetenskapsområdet, Tekniska sektionen, Institutionen för teknikvetenskaper, Mikrosystemteknik.
    Hjort, Klas
    Uppsala universitet, Teknisk-naturvetenskapliga vetenskapsområdet, Tekniska sektionen, Institutionen för teknikvetenskaper, Mikrosystemteknik.
    Klintberg, Lena
    Uppsala universitet, Teknisk-naturvetenskapliga vetenskapsområdet, Tekniska sektionen, Institutionen för teknikvetenskaper, Mikrosystemteknik.
    Thin film metal sensors in fusion bonded glass chips for high-pressure microfluidics2017Ingår i: Journal of Micromechanics and Microengineering, ISSN 0960-1317, E-ISSN 1361-6439, Vol. 27, nr 1, artikel-id 015018Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    High-pressure microfluidics offers fast analyses of thermodynamic parameters for compressed process solvents. However, microfluidic platforms handling highly compressible supercritical CO2 are difficult to control, and on-chip sensing would offer added control of the devices. Therefore, there is a need to integrate sensors into highly pressure tolerant glass chips. In this paper, thin film Pt sensors were embedded in shallow etched trenches in a glass wafer that was bonded with another glass wafer having microfluidic channels. The devices having sensors integrated into the flow channels sustained pressures up to 220 bar, typical for the operation of supercritical CO2. No leakage from the devices could be found. Integrated temperature sensors were capable of measuring local decompression cooling effects and integrated calorimetric sensors measured flow velocities over the range 0.5-13.8 mm/s. By this, a better control of high-pressure microfluidic platforms has been achieved.

  • 11.
    Andersson, Martin
    et al.
    Uppsala universitet, Teknisk-naturvetenskapliga vetenskapsområdet, Tekniska sektionen, Institutionen för teknikvetenskaper, Mikrosystemteknik.
    Hjort, Klas
    Uppsala universitet, Teknisk-naturvetenskapliga vetenskapsområdet, Tekniska sektionen, Institutionen för teknikvetenskaper, Mikrosystemteknik.
    Klintberg, Lena
    Uppsala universitet, Teknisk-naturvetenskapliga vetenskapsområdet, Tekniska sektionen, Institutionen för teknikvetenskaper, Mikrosystemteknik.
    Fracture strength of glass chips for high-pressure microfluidics2016Ingår i: Journal of Micromechanics and Microengineering, ISSN 0960-1317, E-ISSN 1361-6439, Vol. 26, nr 9, artikel-id 095009Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    High-pressure microfluidics exposes new areas in chemistry. In this paper, the reliability of transparent borosilicate glass chips is investigated. Two designs of circular cavities are used for fracture strength tests, either 1.6 mm wide with rounded corners to the fluid inlets, or 2.0 mm wide with sharp inlet corners. Two kinds of tests are done, either short-term,e.g. pressurization to fracture at room temperature, or long-term, with fracture at constant pressurization for up to one week, in the temperature region 11–125 °C. The speed of crack fronts is measured using a high-speed camera. Results show fracture stresses in the range of 129 and 254 MPa for short-term measurements. Long-term measurements conclude the presences of a temperature and stress dependent delayed fracture. For a reliability ofone week at 11–38 °C, a pressure limit is found at the lower end of the short-term measurements, or 15% lower than the average. At 80 °C, this pressure limit is 45% lower. Crack speeds are measured to be 10−5 m s-1 during short-term fracture. These measurements are comparable with estimations based on slow crack growth and show that the growth affects the reliability of glass chips. This effect is strongly affected by high temperatures, thus lowers the operating window of high-pressure glass microfluidic devices.

  • 12.
    Andersson, Martin
    et al.
    Uppsala universitet, Teknisk-naturvetenskapliga vetenskapsområdet, Tekniska sektionen, Institutionen för teknikvetenskaper, Mikrosystemteknik.
    Hjort, Klas
    Uppsala universitet, Teknisk-naturvetenskapliga vetenskapsområdet, Tekniska sektionen, Institutionen för teknikvetenskaper, Mikrosystemteknik.
    Klintberg, Lena
    Uppsala universitet, Teknisk-naturvetenskapliga vetenskapsområdet, Tekniska sektionen, Institutionen för teknikvetenskaper, Mikrosystemteknik.
    High pressure glass microfluidics for supercritical CO2 with aqueous solutions2016Konferensbidrag (Refereegranskat)
    Abstract [en]

    A microfluidic system is presented to investigate interactions between supercritical CO2 and H2O using high-pressure glass chips. The reliability of these chips at pressures necessary to sustain CO2 in the supercritical phase is dependent of both time and temperature. 130 bar can be kept at 38°C for more than a week. These systems can be used to investigate fluid interaction between supercritical CO2 and aqueous solutions by the addition of pH sensitive dye and high speed absorption light imagining, making it possible to demonstrate acidification is in a multiphase chip. By the addition of integrated temperature sensors, better control of the states of the fluids inside the chips can be achieved.

  • 13.
    Andersson, Martin
    et al.
    Uppsala universitet, Teknisk-naturvetenskapliga vetenskapsområdet, Tekniska sektionen, Institutionen för teknikvetenskaper, Mikrosystemteknik.
    Hjort, Klas
    Uppsala universitet, Teknisk-naturvetenskapliga vetenskapsområdet, Tekniska sektionen, Institutionen för teknikvetenskaper, Mikrosystemteknik.
    Klintberg, Lena
    Uppsala universitet, Teknisk-naturvetenskapliga vetenskapsområdet, Tekniska sektionen, Institutionen för teknikvetenskaper, Mikrosystemteknik.
    High-Speed Imaging Of The ph Drop In Aqueous solutions In Contact With Supercritical Co2 Segments2016Konferensbidrag (Övrigt vetenskapligt)
    Abstract [en]

    A high-speed imaging system based on light absorption of bromophenol blue (BPB) pH sensitivedye in a glass high-pressure microchip is used to study the instantaneous dynamics of a pH drop in anaqueous phase in contact with segments of subcritical (liquid) and supercritical CO2. The dynamics ofthe pH-drop has been studied and visualized, demonstrating acidification rates of up to 3.5 pH/s.

  • 14.
    Andersson, Martin
    et al.
    Uppsala universitet, Teknisk-naturvetenskapliga vetenskapsområdet, Tekniska sektionen, Institutionen för teknikvetenskaper, Mikrosystemteknik.
    Klintberg, Lena
    Uppsala universitet, Teknisk-naturvetenskapliga vetenskapsområdet, Tekniska sektionen, Institutionen för teknikvetenskaper, Mikrosystemteknik.
    Hjort, Klas
    Uppsala universitet, Teknisk-naturvetenskapliga vetenskapsområdet, Tekniska sektionen, Institutionen för teknikvetenskaper, Mikrosystemteknik.
    High Pressure Glass Devices For CO2 And H2O2016Konferensbidrag (Övrigt vetenskapligt)
    Abstract [en]

    A microfluidic system is presented to investigate interactions between supercritical CO2 and H2O using high-pressure glass chips. The reliability of these chips at pressures necessary to sustain CO2 in the supercritical phase is dependent of both time and temperature. 130 bar can be kept at 38°C for more than a week. These systems can be used to create parallel flow streams used to investigate reaction dynamics by the addition of pH sensitive dyes. 

  • 15.
    Andersson, Martin
    et al.
    Uppsala universitet, Teknisk-naturvetenskapliga vetenskapsområdet, Tekniska sektionen, Institutionen för teknikvetenskaper, Mikrosystemteknik.
    Klintberg, Lena
    Uppsala universitet, Teknisk-naturvetenskapliga vetenskapsområdet, Tekniska sektionen, Institutionen för teknikvetenskaper, Mikrosystemteknik.
    Svensson, karolina
    Uppsala universitet, Teknisk-naturvetenskapliga vetenskapsområdet, Tekniska sektionen, Institutionen för teknikvetenskaper, Mikrosystemteknik.
    Södergren, Simon
    Uppsala universitet, Teknisk-naturvetenskapliga vetenskapsområdet, Tekniska sektionen, Institutionen för teknikvetenskaper, Mikrosystemteknik.
    Hjort, Klas
    Uppsala universitet, Teknisk-naturvetenskapliga vetenskapsområdet, Tekniska sektionen, Institutionen för teknikvetenskaper, Mikrosystemteknik.
    Microfluidics for High-Pressure Analyses2018Ingår i: 12th Micronano System Workshop (MSW 2018, May 14-15, 2018, Espoo, Finland) / [ed] Samilu Fransilla, 2018, s. 8-8Konferensbidrag (Refereegranskat)
    Abstract [en]

    When using appropriate materials and microfabrication techniques, the small dimensionsand mechanical stability of microstructured devices allow for processes at high pressureswithout loss in safety. The largest area of applications has been demonstrated in chemistry,where extraction, synthesis and analyses often excel at high densities and high temperatures.These two parameters are accessible through high pressures. Capillary chemistry has beenused since long but, just like in low-pressure applications, there are several advantages in usingmicrofluidic platforms for control of reactions, catalysis, mixing and separation. For example,planar isothermal set-ups, large local variations in geometries, dense form factors, small deadvolumes and precisely positioned microstructures.In analytical systems, we are studying high-pressure components and microsystems forsampling, sample preparation, analyses and fractionation. We will present what drives ourresearch and development: Our experimental set-up with high-pressure pumps, high-speedcamera, sensors, valves, piston-chambers, backpressure regulators, cooling table, etc. How wehave built capability in pumping and valving by the use of stainless steel and paraffinactuation. How we are making high pressure silicon-glass and glass-glass chips with integratedelectrical thin film sensors, using printed circuit boards to ease handling of the chips andintegrating modules. A set of relevant publications are listed below.

  • 16.
    Andersson, Martin
    et al.
    Uppsala universitet, Teknisk-naturvetenskapliga vetenskapsområdet, Tekniska sektionen, Institutionen för teknikvetenskaper, Mikrosystemteknik.
    Knaust, Stefan
    Uppsala universitet, Teknisk-naturvetenskapliga vetenskapsområdet, Tekniska sektionen, Institutionen för teknikvetenskaper, Mikrosystemteknik.
    Ogden, Sam
    Uppsala universitet, Teknisk-naturvetenskapliga vetenskapsområdet, Tekniska sektionen, Institutionen för teknikvetenskaper, Mikrosystemteknik.
    Hjort, Klas
    Uppsala universitet, Teknisk-naturvetenskapliga vetenskapsområdet, Tekniska sektionen, Institutionen för teknikvetenskaper, Mikrosystemteknik.
    Bodén, Roger
    Uppsala universitet, Teknisk-naturvetenskapliga vetenskapsområdet, Tekniska sektionen, Institutionen för teknikvetenskaper, Mikrosystemteknik.
    Integrated high-pressure fluid manipulation in microfluidic systems2014Konferensbidrag (Övrigt vetenskapligt)
  • 17.
    Andersson, Martin
    et al.
    Uppsala universitet, Teknisk-naturvetenskapliga vetenskapsområdet, Tekniska sektionen, Institutionen för teknikvetenskaper, Mikrosystemteknik.
    Mårtensson, Gustaf
    EMSL, MC2, Chalmers University of Technology, Göteborg, Sweden.
    Klintberg, Lena
    Uppsala universitet, Teknisk-naturvetenskapliga vetenskapsområdet, Tekniska sektionen, Institutionen för teknikvetenskaper, Mikrosystemteknik.
    Flowing and pressurizing a solid-liquid two phase monodispersed fluid with high solid content in a transparent microfluidic high-pressure chip2017Konferensbidrag (Refereegranskat)
  • 18.
    Andersson, Martin
    et al.
    Uppsala universitet, Teknisk-naturvetenskapliga vetenskapsområdet, Tekniska sektionen, Institutionen för teknikvetenskaper, Mikrosystemteknik.
    Mårtensson, Gustav
    Mycronic AB, Täby.; Chalmers Univ Technol, MC2, EMSL, Gothenburg.
    Klintberg, Lena
    Uppsala universitet, Teknisk-naturvetenskapliga vetenskapsområdet, Tekniska sektionen, Institutionen för teknikvetenskaper, Mikrosystemteknik.
    Flowing and pressurizing a solid-liquid two phase monodispersed fluid with high solid content in a transparent microfluidic high-pressure chip2017Ingår i: 28TH MICROMECHANICS AND MICROSYSTEMS EUROPE WORKSHOP, IOP PUBLISHING LTD , 2017, artikel-id UNSP 012010Konferensbidrag (Refereegranskat)
    Abstract [en]

    Handling highly concentrated solid-liquid two-phase fluids in microfluidics is challenging. In this paper, we present the first studies of flowing solder paste with a high solid content in a transparent high-pressure tolerant glass chip, thereby increasing the understanding of how multiphase liquids with high density difference between the phases behave in small channels (840 mu m in diameter). The system, including a custom made high-pressure, low resistance, interface, was continuously operated at pressures up to of 6 MPa and devices where shown to have pressure tolerance up to 17 MPa. During flow through the chip, the packing density of the solder balls displayed inhomogeneity over the channel where chains of solder balls in contact with each other were formed together with voids. These in-homogeneities persisted along the channel during flow. The flow rate of the paste through the chip oscillated between 63 to 350 mu m/s when pumping at constant volume rate of 30 mu l/min. When a pressure of 2 MPa was applied, the volume of the solder paste particle segment decreased 1.6%, and 0.1% was elastically recovered when the pressure was released. It is concluded that this transparent microfluidic high-pressure glass chip with the special developed interface is suitable for flow studies of solder paste with a high solid content.

  • 19.
    Andersson, Martin
    et al.
    Uppsala universitet, Teknisk-naturvetenskapliga vetenskapsområdet, Tekniska sektionen, Institutionen för teknikvetenskaper, Mikrosystemteknik.
    Rodriguez-Meizoso, Irene
    Turner, Charlotta
    Hjort, Klas
    Uppsala universitet, Teknisk-naturvetenskapliga vetenskapsområdet, Tekniska sektionen, Institutionen för teknikvetenskaper, Mikrosystemteknik.
    Klintberg, Lena
    Uppsala universitet, Teknisk-naturvetenskapliga vetenskapsområdet, Tekniska sektionen, Institutionen för teknikvetenskaper, Mikrosystemteknik.
    Dynamic pH determination at high pressure of aqueous additive mixtures in contact with dense CO22018Ingår i: Journal of Supercritical Fluids, ISSN 0896-8446, E-ISSN 1872-8162, Vol. 136, s. 95-101Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    A system consisting of a high-pressure tolerant microfluidic glass chip, high-speed absorbance imaging, and image processing has been developed to study rapid dynamic events like pH change in a multiphase flow. The system gives both kinetic and quantitative equilibrated information. By tracking the interactions of aqueous additive mixtures and liquid CO2, at 80 bar and 24 °C, under flow, measurement at a given P, T condition is done in 0.25 s. The acidification rate to steady state was found to be mass transport limited, occurring in less than 1 s. For 30 mM of the additives ammonium acetate and ammonium formate, equilibrium pH of 4.5 and 4.1, respectively, was seen. These additives are of key importance in common mobile phases used in SFC.

  • 20.
    Andersson, Martin
    et al.
    Uppsala universitet, Teknisk-naturvetenskapliga vetenskapsområdet, Tekniska sektionen, Institutionen för teknikvetenskaper, Mikrosystemteknik.
    Stocklassa, Jesper
    Uppsala universitet, Teknisk-naturvetenskapliga vetenskapsområdet, Tekniska sektionen, Institutionen för teknikvetenskaper, Mikrosystemteknik.
    Klintberg, Lena
    Uppsala universitet, Teknisk-naturvetenskapliga vetenskapsområdet, Tekniska sektionen, Institutionen för teknikvetenskaper, Mikrosystemteknik.
    Hjort, Klas
    Uppsala universitet, Teknisk-naturvetenskapliga vetenskapsområdet, Tekniska sektionen, Institutionen för teknikvetenskaper, Mikrosystemteknik.
    Control Systems For Gas-Expanded Liquids In Microreactors2017Konferensbidrag (Refereegranskat)
  • 21.
    Andersson, Martin
    et al.
    Uppsala universitet, Teknisk-naturvetenskapliga vetenskapsområdet, Tekniska sektionen, Institutionen för teknikvetenskaper, Mikrosystemteknik.
    Svensson, Karolina
    Uppsala universitet, Teknisk-naturvetenskapliga vetenskapsområdet, Tekniska sektionen, Institutionen för teknikvetenskaper, Mikrosystemteknik.
    Klintberg, Lena
    Uppsala universitet, Teknisk-naturvetenskapliga vetenskapsområdet, Tekniska sektionen, Institutionen för teknikvetenskaper, Mikrosystemteknik.
    Hjort, Klas
    Uppsala universitet, Teknisk-naturvetenskapliga vetenskapsområdet, Tekniska sektionen, Institutionen för teknikvetenskaper, Mikrosystemteknik.
    A microfluidic control board for high-pressure flow, composition, and relative permittivity2018Ingår i: Analytical Chemistry, ISSN 0003-2700, E-ISSN 1520-6882, Vol. 90, nr 21, s. 12601-12608Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    Flow control is central to microfluidics and chromatography. With decreasing dimensions and high pressures, precise fluid flows are often needed. In this paper, a high-pressure flow control system is presented, allowing for the miniaturization of chromatographic systems and the increased performance of microfluidic setups by controlling flow, composition and relative permittivity of two-component flows with CO2. The system consists of four chips: two flow actuator chips, one mixing chip and one relative permittivity sensor. The actuator chips, throttling the flow, required no moving parts as they instead relied on internal heaters to change the fluid resistance. This allows for flow control using miniaturized fluid delivery systems containing only a single pump or pressure source. Mobile phase gradients between 49% to 74% methanol in CO2 were demonstrated. Depending on how the actuator chips were dimensioned, the position of this range could be set for different method-specific needs. With the microfluidic control board, both flow and composition could be controlled from constant pressure sources, drift could be removed, and variations in composition could be lowered by 84%, resulting in microflows of CO2 and methanol with a variation in the composition of 0.30%.

  • 22.
    Andersson, Martin
    et al.
    Uppsala universitet, Teknisk-naturvetenskapliga vetenskapsområdet, Tekniska sektionen, Institutionen för teknikvetenskaper, Mikrosystemteknik.
    Wilson, Anton
    Uppsala universitet, Teknisk-naturvetenskapliga vetenskapsområdet, Tekniska sektionen, Institutionen för teknikvetenskaper, Mikrosystemteknik.
    Hjort, Klas
    Uppsala universitet, Teknisk-naturvetenskapliga vetenskapsområdet, Tekniska sektionen, Institutionen för teknikvetenskaper, Mikrosystemteknik.
    Klintberg, Lena
    Uppsala universitet, Teknisk-naturvetenskapliga vetenskapsområdet, Tekniska sektionen, Institutionen för teknikvetenskaper, Mikrosystemteknik.
    A microfluidic relative permittivity sensor for feedback control of carbon dioxide expanded liquid flows2019Ingår i: Sensors and Actuators A-Physical, ISSN 0924-4247, E-ISSN 1873-3069, Vol. 285, s. 165-172Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    Binary CO2-alcohol mixtures, such as CO2-expanded liquids (CXLs), are promising green solvents for reaching higher performance in flow chemistry and separation processing. However, their compressibility and high working pressure makes handling challenging. These mixtures allow for a tuneable polarity but, to do so, requires precise flow control. Here, a high-pressure tolerant microfluidic system containing a relative permittivity sensor and a mixing chip is used to actively regulate the relative permittivity of these fluids and indirectly—composition. The sensor is a fluid-filled plate capacitor created using embedded 3D-structured thin films and has a linearity of 0.9999, a sensitivity of 4.88 pF per unit of relative permittivity, and a precision within 0.6% for a sampling volume of 0.3 μL. Composition and relative permittivity of CO2-ethanol mixtures were measured at 82 bar and 21 °C during flow. By flow and dielectric models, this relationship was found to be described by the pure components and a quadratic mixing rule with an interaction parameter, kij, of -0.63 ± 0.02. Microflows with a relative permittivity of 1.7–21.4 were generated, and using the models, this was found to correspond to compositions of 6–90 mol % ethanol in CO2. With the sensor, a closed loop control system was realised and CO2-ethanol flows were tuned to setpoints of the relative permittivity in 30 s.

  • 23.
    Arbat, Anna
    et al.
    SIC, Departament d’Electrònica, Universitat de Barcelona, Barcelona, Spain.
    Edqvist, Erik
    Uppsala universitet, Teknisk-naturvetenskapliga vetenskapsområdet, Tekniska sektionen, Institutionen för teknikvetenskaper, Mikrosystemteknik.
    Casanova Mohr, Raimon
    SIC, Departament d’Electrònica, Universitat de Barcelona, Barcelona, Spain.
    Brufau, Jordi
    SIC, Departament d’Electrònica, Universitat de Barcelona, Barcelona, Spain.
    Canals, J.
    SIC, Departament d’Electrònica, Universitat de Barcelona, Barcelona, Spain.
    Samitier, Joseph
    SIC, Departament d’Electrònica, Universitat de Barcelona, Barcelona, Spain.
    Johansson, Stefan
    Uppsala universitet, Teknisk-naturvetenskapliga vetenskapsområdet, Tekniska sektionen, Institutionen för teknikvetenskaper, Mikrosystemteknik.
    Dieguez, Angle
    SIC, Departament d’Electrònica, Universitat de Barcelona, Barcelona, Spain.
    Design and validation of the control circuits for a micro-cantilever tool for a micro-robot2009Ingår i: Sensors and Actuators A-Physical, ISSN 0924-4247, E-ISSN 1873-3069, Vol. 153, nr 1, s. 76-83Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    The objective of this paper is to present the design and validation of a cantilever-based contact sensing system for a micro-robot. Key elements of the fabrication process of the sensor and the electrical model extraction used to design the control electronics are described. The architecture used for the sensor corresponds to a micro-cantilever fabricated of piezoelectric-polyvinylidene fluoride-trifluoroethylene stacked in a multilayer structure with the possibility of both actuating and sensing. A lumped electro mechanical equivalent model of the micro-cantilever was used to design the control electronics for the cantilever. A driving signal from, the control system is used to vibrate the cantilever at its first mechanical resonance frequency. The control system contains an analog front-end to measure the sensor output signal and a digital control unit designed to track and keep the resonance frequency of the cantilever. By integrating the cantilever control system is integrated in the application specified integrated circuit used to control of the circuit is simplyfied and very compact. Experimental results show a similar behavior between the electrical model and the fabricated system, and the deviations between the model and the measured structure are analyzed. The results also show that the designed control system is capable to detect the resonance frequency of the system and to actuate despite small deviations in process parameters of different batches of cantilevers. The whole system was designed to be integrated into an autonomous micro-robot, although it can be used in other applications.

  • 24.
    Atif, Abdul Raouf
    et al.
    Uppsala universitet, Teknisk-naturvetenskapliga vetenskapsområdet, Tekniska sektionen, Institutionen för teknikvetenskaper, Mikrosystemteknik.
    Carter, Sarah-Sophia
    Uppsala universitet, Teknisk-naturvetenskapliga vetenskapsområdet, Tekniska sektionen, Institutionen för teknikvetenskaper, Mikrosystemteknik.
    Pujari-Palmer, Michael
    Uppsala universitet, Teknisk-naturvetenskapliga vetenskapsområdet, Tekniska sektionen, Institutionen för teknikvetenskaper, Tillämpad materialvetenskap.
    Tenje, Maria
    Uppsala universitet, Teknisk-naturvetenskapliga vetenskapsområdet, Tekniska sektionen, Institutionen för teknikvetenskaper, Mikrosystemteknik.
    Mestres, Gemma
    Uppsala universitet, Teknisk-naturvetenskapliga vetenskapsområdet, Tekniska sektionen, Institutionen för teknikvetenskaper, Mikrosystemteknik.
    Bone Cement Embedded in a Microfluidic Device2018Konferensbidrag (Refereegranskat)
    Abstract [en]

    Calcium phosphate cements (CPCs) have a great potential in the treatment of bone disorders due to their excellent biocompatibility. Although CPCs are promising when implanted in vivo, there is poor correlation between in vitro and in vivo studies. This could be because most conventional in vitro systems lack a 3D architecture, or dynamic conditions (i.e. a continuous refreshment stream). The aim of this work is to embed CPCs into a microfluidic system and evaluate ion and protein exchange at different flow rates.

  • 25.
    Atif, Abdul Raouf
    et al.
    Uppsala universitet, Teknisk-naturvetenskapliga vetenskapsområdet, Tekniska sektionen, Institutionen för teknikvetenskaper, Mikrosystemteknik.
    Pujari-Palmer, Michael
    Uppsala universitet, Teknisk-naturvetenskapliga vetenskapsområdet, Tekniska sektionen, Institutionen för teknikvetenskaper, Tillämpad materialvetenskap.
    Tenje, Maria
    Uppsala universitet, Teknisk-naturvetenskapliga vetenskapsområdet, Tekniska sektionen, Institutionen för teknikvetenskaper, Mikrosystemteknik.
    Mestres, Gemma
    Uppsala universitet, Teknisk-naturvetenskapliga vetenskapsområdet, Tekniska sektionen, Institutionen för teknikvetenskaper, Mikrosystemteknik.
    Evaluation of Ionic Interactions of Bone Cement-on-Chip2019Konferensbidrag (Övrigt vetenskapligt)
    Abstract [en]

    INTRODUCTION: Biomaterials are synthetic materials that can be incorporated into the body to replace an impaired physiological function. Apatite calcium phosphate cements (CPCs), used for bone regeneration, give calcium-deficient hydroxyapatite (CDHA) as an end-product after a dissolution-precipitation reaction during fabrication. CDHA has a tendency to uptake calcium and release phosphate into cell culture medium. Potentially, this leads to depletion of calcium ions in solution, which can be detrimental to cell survival. The aim of this work is to embed CDHA in a microfluidic system and evaluate ion exchange at different flow rates.

    METHODS: CPC paste was cast into a 0.8mm pocket within a Polydimethylsiloxane (PDMS, cured at 60°C for 2h) mould. CPCs were set in 0.9% w/v NaCl at 37°C for 10 days resulting in CDHA. The PDMS containing the CDHA was then bonded to glass, leaving a 0.5mm channel gap. Minimum Essential Media (MEM, 1ml) was pumped through the channel at low (2µl/min), medium (8µl/min) and high (14µl/min) flow rates. A CDHA disc (ø=15mm, h=2mm) was immersed in MEM (1ml) at static conditions (0µl/min) for 24h. Stock Media was taken as control. Calcium and phosphorus concentrations were analysed using Inductively Coupled Plasma Optical Emission Spectroscopy.

    RESULTS & CONCLUSIONS: CDHA was successfully embedded in a microfluidic chip (Fig. 1A). Observed [Ca] and [P] levels were closer to levels in stock MEM at higher flow rates (Fig. 1B). We anticipate that osteoblast viability will improve when grown under flow, as opposed to static conditions, due to continuous replenishment of cell medium.

  • 26.
    Barkefors, Irmeli
    et al.
    Uppsala universitet, Medicinska och farmaceutiska vetenskapsområdet, Medicinska fakulteten, Institutionen för medicinsk biokemi och mikrobiologi.
    Thorslund, Sara
    Uppsala universitet, Teknisk-naturvetenskapliga vetenskapsområdet, Tekniska sektionen, Institutionen för teknikvetenskaper, Mikrosystemteknik.
    Nikolajeff, Fredrik
    Uppsala universitet, Teknisk-naturvetenskapliga vetenskapsområdet, Tekniska sektionen, Institutionen för teknikvetenskaper, Mikrosystemteknik.
    Kreuger, Johan
    Uppsala universitet, Medicinska och farmaceutiska vetenskapsområdet, Medicinska fakulteten, Institutionen för medicinsk biokemi och mikrobiologi.
    A fluidic device to study directional angiogenesis in complex tissue and organ culture models2009Ingår i: Lab on a Chip, ISSN 1473-0197, E-ISSN 1473-0189, Vol. 9, nr 4, s. 529-535Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    Many signals that induce angiogenesis have been identified; however, it is still not clear how these signals interact to shape the vascular system. We have developed a fluidic device for generation of molecular gradients in 3-dimensional cultures of complex tissues and organs in order to create an assay for precise induction and guidance of growing blood vessels. The device features a centrally placed culture chamber, flanked by channels attached to a perfusion system used to generate gradients. A separate network of vacuum channels permits reversible attachment of the device to a flat surface. We show that the fluidic device can be used to create growth factor gradients that induce directional angiogenesis in embryonic mouse kidneys and in clusters of differentiating stem cells. These results demonstrate that the device can be used to accurately manipulate complex morphogenetic processes with a high degree of experimental control.

  • 27. Bejhed, Johan
    et al.
    Nguyen, Hugo
    Uppsala universitet, Teknisk-naturvetenskapliga vetenskapsområdet, Tekniska sektionen, Institutionen för teknikvetenskaper, Materialvetenskap. Materialvetenskap.
    Åstrand, Peter
    Eriksson, Anders
    Uppsala universitet, Teknisk-naturvetenskapliga vetenskapsområdet, Tekniska sektionen, Institutionen för teknikvetenskaper, Mikrosystemteknik.
    Köhler, Johan
    Uppsala universitet, Teknisk-naturvetenskapliga vetenskapsområdet, Tekniska sektionen, Institutionen för teknikvetenskaper, Mikrosystemteknik.
    Numeric modeling and verification of crossed v-groove particle filters2006Ingår i: Journal of Michromechanics and MicroengineeringArtikel i tidskrift (Refereegranskat)
  • 28.
    Berglund, Martin
    Uppsala universitet, Teknisk-naturvetenskapliga vetenskapsområdet, Tekniska sektionen, Institutionen för teknikvetenskaper, Mikrosystemteknik, Ångström Space Technology Centre (ÅSTC).
    Miniature Plasma Sources for High-Precision Molecular Spectroscopy in Planetary Exploration2015Doktorsavhandling, sammanläggning (Övrigt vetenskapligt)
    Abstract [en]

    The prospect of finding life outside Earth has fascinated mankind for ages, and new technology continuously pushes the boundary of how remote and how obscure evidence we can find. Employing smaller, or completely new, types of landers and robots, and equipping them with miniature instruments would indeed revolutionize exploration of other planets and moons.

    In this thesis, microsystems technology is used to create a miniature high-precision isotope-resolving molecular spectrometer utilizing the optogalvanic effect. The heart of the instrument, as well as this thesis, is a microplasma source.

    The plasma source is a split-ring resonator, chosen for its simplicity, pressure range and easily accessible plasma, and modified to fit the challenging application, e.g., by the adding of an additional ground plane for improved electromagnetic shielding, and the integration of microscopic plasma probes to extract the pristine optogalvanic signal.

    Plasma sources of this kind have been manufactured in both printed circuit board and alumina, the latter for its chemical inertness and for compatibility with other devices in a total analysis system. From previous studies, classical optogalvanic spectroscopy (OGS), although being very sensitive, is known to suffer from stability and reproducibility issues. In this thesis several studies were conducted to investigate and improve these shortcomings, and to improve the signal-to-noise ratio. Moreover, extensive work was put into understanding the underlying physics of the technique.

    The plasma sources developed here, are the first ever miniature devices to be used in OGS, and exhibits several benefits compared to traditional solutions. Furthermore, it has been confirmed that OGS scales well with miniaturization. For example, the signal strength does not decrease as the volume is reduced like in regular absorption spectroscopy. Moreover, the stability and reproducibility are greatly increased, in some cases as much as by two orders of magnitude, compared with recent studies made on a classical OGS setup. The signal-to-noise ratio has also been greatly improved, e.g., by enclosing the sample cell and by biasing the plasma. Another benefit of a miniature sample cell is the miniscule amount of sample it requires, which can be important in many applications where only small amounts of sample are available.

    To conclude: With this work, an important step toward a miniature, yet highly performing, instrument for detection of extraterrestrial life, has been taken.

    Delarbeten
    1. Operation characteristics and optical emission distribution of a miniaturized silicon through-substrate split-ring resonator microplasma source
    Öppna denna publikation i ny flik eller fönster >>Operation characteristics and optical emission distribution of a miniaturized silicon through-substrate split-ring resonator microplasma source
    2014 (Engelska)Ingår i: Journal of microelectromechanical systems, ISSN 1057-7157, E-ISSN 1941-0158, Vol. 23, nr 6, s. 1340-1345Artikel i tidskrift (Refereegranskat) Published
    Abstract [en]

    There are many new microplasma sources being developed for a wide variety of applications, each with different properties tailored to its specific use. Microplasma sources enable portable instruments for, e.g., chemical analysis, sterilization, or activation of substances. A novel microplasma source, based on a microstrip split-ring resonator design with electrodes integrated in its silicon substrate, was designed, manufactured, and evaluated. This device has a plasma discharge gap with a controlled volume and geometry, and offers straightforward integration with other microelectromechancial systems (MEMS) components, e.g., microfluidics. The realized device was resonant at around 2.9 GHz with a quality factor of 18.7. Two different operational modes were observed with the plasma at high pressure being confined in the gap between the electrodes, whereas the plasma at low pressures appeared between the ends of the electrodes on the backside. Measurement of the angular distribution of light emitted from the device with through-substrate electrodes showed narrow emission lobes compared with a reference plasma source with on-substrate electrodes.

    Nationell ämneskategori
    Fysik Teknik och teknologier
    Identifikatorer
    urn:nbn:se:uu:diva-239111 (URN)10.1109/JMEMS.2014.2312849 (DOI)000345851100010 ()
    Tillgänglig från: 2015-01-05 Skapad: 2014-12-18 Senast uppdaterad: 2017-12-05Bibliografiskt granskad
    2. Evaluation of a microplasma source based on a stripline split-ring resonator
    Öppna denna publikation i ny flik eller fönster >>Evaluation of a microplasma source based on a stripline split-ring resonator
    2013 (Engelska)Ingår i: Plasma sources science & technology (Print), ISSN 0963-0252, E-ISSN 1361-6595, Vol. 22, nr 5, s. 055017-Artikel i tidskrift (Refereegranskat) Published
    Abstract [en]

    In this paper, a stripline split-ring resonator microwave-induced plasma source, aimed for integration in complex systems, is presented and compared with a traditional microstrip design. Devices based on the two designs are evaluated using a plasma breakdown test setup for measuring the power required to ignite plasmas at different pressures. Moreover, the radiation efficiency of the devices is investigated with a Wheeler cap, and their electromagnetic compatibility is investigated in a variable electrical environment emulating an application. Finally, the basic properties of the plasma in the two designs are investigated in terms of electron temperature, plasma potential and ion density. The study shows that, with a minor increase in plasma ignition power, the stripline design provides a more isolated and easy-to-integrate alternative to the conventional microstrip design. Moreover, the stripline devices showed a decreased antenna efficiency as compared with their microstrip counterparts, which is beneficial for plasma sources. Furthermore, the investigated stripline devices exhibited virtually no frequency shift in a varying electromagnetic environment, whereas the resonance frequency of their microstrip counterparts shifted up to 17.5%. With regard to the plasma parameters, the different designs showed only minor differences in electron temperature, whereas the ion density was higher with the stripline design.

    Ort, förlag, år, upplaga, sidor
    Institute of Physics (IOP), 2013
    Nyckelord
    Split-ring resonator, Microwave plasma, Microstrip, Stripline, Plasma, Wheeler cap, Langmuir probe
    Nationell ämneskategori
    Annan fysik Teknik och teknologier
    Forskningsämne
    Teknisk fysik med inriktning mot mikrosystemteknik; Teknisk fysik med inriktning mot mikrovågsteknik
    Identifikatorer
    urn:nbn:se:uu:diva-206792 (URN)10.1088/0963-0252/22/5/055017 (DOI)000325246400017 ()
    Tillgänglig från: 2013-09-04 Skapad: 2013-09-04 Senast uppdaterad: 2017-12-06Bibliografiskt granskad
    3. Microplasma source for optogalvanic spectroscopy of nanogram samples
    Öppna denna publikation i ny flik eller fönster >>Microplasma source for optogalvanic spectroscopy of nanogram samples
    2013 (Engelska)Ingår i: Journal of Applied Physics, ISSN 0021-8979, E-ISSN 1089-7550, Vol. 114, nr 3, s. 033302-Artikel i tidskrift (Refereegranskat) Published
    Abstract [en]

    The demand for analysis of smaller samples in isotopic ratio measurements of rare isotopes is continuously rising with the development of new applications, particularly in biomedicine. Interesting in this aspect are methods based on optogalvanic spectroscopy, which have been reported to facilitate both 13C-to-12C and 14C-to-12C ratio measurements with high sensitivity. These methods also facilitate analysis of very small samples, down to the microgram range, which makes them very competitive to other technologies, e.g., accelerator mass spectroscopy. However, there exists a demand for moving beyond the microgram range, especially from regenerative medicine, where samples consist of, e.g., DNA, and, hence, the total sample amount is extremely small. Making optogalvanic spectroscopy of carbon isotopes applicable to such small samples, requires miniaturization of the key component of the system, namely the plasma source, in which the sample is ionized before analysis. In this paper, a novel design of such a microplasma source based on a stripline split-ring resonator is presented and evaluated in a basic optogalvanic spectrometer. The investigations focus on the capability of the plasma source to measure the optogalvanic signal in general, and the effect of different system and device specific parameters on the amplitude and stability of the optogalvanic signal in particular. Different sources of noise and instabilities are identified, and methods of mitigating these issues are discussed. Finally, the ability of the cell to handle analysis of samples down to the nanogram range is investigated, pinpointing the great prospects of stripline split-ring resonators in optogalvanic spectroscopy.

    Ort, förlag, år, upplaga, sidor
    American Institute of Physics (AIP), 2013
    Nyckelord
    nanostructured materials, optogalvanic spectroscopy, plasma instability, plasma probes, plasma sources, strip line resonators
    Nationell ämneskategori
    Annan fysik Teknik och teknologier
    Forskningsämne
    Teknisk fysik med inriktning mot mikrosystemteknik; Teknisk fysik med inriktning mot jonfysik; Teknisk fysik med inriktning mot mikrovågsteknik
    Identifikatorer
    urn:nbn:se:uu:diva-204156 (URN)10.1063/1.4813414 (DOI)000322202700014 ()
    Tillgänglig från: 2013-07-22 Skapad: 2013-07-22 Senast uppdaterad: 2017-12-06Bibliografiskt granskad
    4. Stripline split-ring resonator with integrated optogalvanic sample cell
    Öppna denna publikation i ny flik eller fönster >>Stripline split-ring resonator with integrated optogalvanic sample cell
    Visa övriga...
    2014 (Engelska)Ingår i: Laser Physics Letters, ISSN 1612-2011, Vol. 11, nr 4, s. 045701-Artikel i tidskrift, Letter (Refereegranskat) Published
    Abstract [en]

    Intracavity optogalvanic spectroscopy (ICOGS) has been proposed as a method for unambiguous detection of rare isotopes. Of particular interest is 14C, where detection of extremely low concentrations in the 1:1015 range (14C:12C), is of interest in, e.g., radiocarbon dating and pharmaceutical sciences. However, recent reports show that ICOGS suffers from substantial problems with reproducibility. To qualify ICOGS as an analytical method, more stable and reliable plasma generation and signal detection are needed. In our proposed setup, critical parameters have been improved. We have utilized a stripline split-ring resonator microwave-induced microplasma source to excite and sustain the plasma. Such a microplasma source offers several advantages over conventional ICOGS plasma sources. For example, the stripline split-ring resonator concept employs separated plasma generation and signal detection, which enables sensitive detection at stable plasma conditions. The concept also permits in situ observation of the discharge conditions, which was found to improve reproducibility. Unique to the stripline split-ring resonator microplasma source of in this study, is that the optogalvanic sample cell has been embedded in the device itself. This integration enabled improved temperature control and more stable and accurate signal detection. Significant improvements are demonstrated, including reproducibility, signal-to-noise ratio and precision.

    Ort, förlag, år, upplaga, sidor
    Institute of Physics (IOP), 2014
    Nyckelord
    Optogalvanic spectroscopy, Laser-assisted ratio analyzer, Split-ring resonator, microwave-induced microplasma source
    Nationell ämneskategori
    Atom- och molekylfysik och optik Fusion, plasma och rymdfysik Annan materialteknik
    Forskningsämne
    Fysik; Teknisk fysik med inriktning mot mikrosystemteknik
    Identifikatorer
    urn:nbn:se:uu:diva-218769 (URN)10.1088/1612-2011/11/4/045701 (DOI)000332768800011 ()
    Forskningsfinansiär
    Vetenskapsrådet, A0442201
    Tillgänglig från: 2014-02-17 Skapad: 2014-02-17 Senast uppdaterad: 2015-05-12Bibliografiskt granskad
    5. Improved optogalvanic detection with voltage biased Langmuir probes
    Öppna denna publikation i ny flik eller fönster >>Improved optogalvanic detection with voltage biased Langmuir probes
    2014 (Engelska)Ingår i: Journal of Applied Physics, ISSN 0021-8979, E-ISSN 1089-7550, Vol. 116, nr 24, s. 243301-Artikel i tidskrift (Refereegranskat) Published
    Abstract [en]

    Optogalvanic detectors show great potential for infrared spectroscopy, especially in cavity enhanced techniques where they, in contrast to ordinary absorption detectors, can perform intracavity measurements. This enables them to utilize the signal-to-noise ratio improvement gained from the extended effective path length inside an optical cavity, without losing signal strength due to the limited amount of light exiting through the rear mirror. However, if optogalvanic detectors are to become truly competitive, their intrinsic sensitivity and stability has to be improved. This, in turn, requires a better understanding of the mechanisms behind the generation of the optogalvanic signal. The study presented here focuses on an optogalvanic detector based on a miniaturized stripline split-ring resonator plasma source equipped with Langmuir probes for detecting the optogalvanic signal. In particular, the effect of applying a constant bias voltage to one of the probes is investigated, both with respect to the sensitivity and stability, and to the mechanism behind the generation of the signal. Experiments with different bias voltages at different pressures and gas composition have been conducted. In particular, two different gas compositions (pure CO2 and 0.25% CO2 in 99.75% N-2) at six different pressures (100 Pa to 600 Pa) have been studied. It has been shown that probe biasing effectively improves the performance of the detector, by increasing the amplitude of the signal linearly over one order of magnitude, and the stability by about 40% compared with previous studies. Furthermore, it has been shown that relatively straightforward plasma theory can be applied to interpret the mechanism behind the generation of the signal, although additional mechanisms, such as rovibrational excitation from electron-molecule collisions, become apparent in CO2 plasmas with electron energies in the 1-6 eV range. With the achieved performance improvement and the more solid theoretical framework presented here, stripline split-ring resonator optogalvanic detectors can evolve into a compact, inexpensive, and easy-to-operate alternative for future infrared spectrometers. (C) 2014 AIP Publishing LLC.

    Nationell ämneskategori
    Fysik
    Identifikatorer
    urn:nbn:se:uu:diva-242865 (URN)10.1063/1.4904964 (DOI)000347164300003 ()
    Tillgänglig från: 2015-02-04 Skapad: 2015-02-02 Senast uppdaterad: 2017-12-05Bibliografiskt granskad
    6. Evaluation of dielectric properties of HTCC alumina for realization of plasma sources
    Öppna denna publikation i ny flik eller fönster >>Evaluation of dielectric properties of HTCC alumina for realization of plasma sources
    2015 (Engelska)Ingår i: Journal of Electronic Materials, ISSN 0361-5235, E-ISSN 1543-186X, Vol. 44, nr 10, s. 3654-3660Artikel i tidskrift (Refereegranskat) Published
    Abstract [en]

    As the sensitivity of optogalvanic spectroscopy based on prototype microplasma sources increases, contamination from composite materials in the printed circuit board used starts to become a concern. In this paper, a transfer to high-temperature cofired alumina and platinum is made and evaluated. The high-purity alumina provides an inert plasma environment, and allows for temperatures above 1000A degrees C, which is beneficial for future integration of a combustor. To facilitate the design of high-end plasma sources, characterization of the radio frequency (RF) parameters of the materials around 2.6 GHz is carried out. A RF resonator structure was fabricated in both microstrip and stripline configurations. These resonators were geometrically and electrically characterized, and epsilon (r) and tan were calculated using the RF waveguide design tool Wcalc. The resulting epsilon (r) for the microstrip and stripline was found to be 10.68 (+/- 0.12) and 9.65 (+/- 0.14), respectively. The average tan of all devices was found to be 0.0011 (+/- 0.0007). With these parameters, a series of proof-of-concept plasma sources were fabricated and evaluated. Some problems in the fabrication stemmed from the lamination and difficulties with the screen-printing, but a functioning plasma source was demonstrated.

    Nationell ämneskategori
    Keramteknik Teknik och teknologier Fysik
    Forskningsämne
    Teknisk fysik med inriktning mot mikrosystemteknik
    Identifikatorer
    urn:nbn:se:uu:diva-251300 (URN)10.1007/s11664-015-3901-7 (DOI)000360672900061 ()
    Forskningsfinansiär
    RymdstyrelsenKnut och Alice Wallenbergs Stiftelse
    Tillgänglig från: 2015-04-15 Skapad: 2015-04-15 Senast uppdaterad: 2017-12-04Bibliografiskt granskad
    7. Manufacturing Miniature Langmuir probes by Fusing Platinum Bond Wires
    Öppna denna publikation i ny flik eller fönster >>Manufacturing Miniature Langmuir probes by Fusing Platinum Bond Wires
    2015 (Engelska)Ingår i: Journal of Micromechanics and Microengineering, ISSN 0960-1317, E-ISSN 1361-6439, Vol. 25, nr 10, artikel-id 105012Artikel i tidskrift (Refereegranskat) Published
    Abstract [en]

    This paper reports on a novel method for manufacturing microscopic Langmuir probes with spherical tips from platinum bond wires for plasma characterization in microplasma sources by fusing. Here, the resulting endpoints, formed by droplets of a fused wire, are intended to act as a spherical Langmuir probe. For studying the fusing behavior, bond wires were wedge-bonded over a 2 mm wide slit, to emulate the final application, and fused at different currents and voltages. For electrical isolation, a set of wires were coated with a 4 µm thick layer of Parylene before they were fused. After fusing, the gap size, as well as the shape and area of the ends of the remaining stubs were measured. The yield of the process was also investigated, and the fusing event was studied using a high-speed camera for analyzing the dynamics of fusing. Four characteristic tip shapes were observed: spherical, semi-spherical, serpentine shaped and folded. The stub length leveled out at ~420µm. The fusing of the coated wires required a higher power for attaining a spherical shape. Finally, a Parylene coated bond wire was integrated into a stripline split-ring resonator (SSRR) microplasma source, and fused to form two Langmuir probes with spherical endpoints. These probes were used for measuring the I-V characteristics of a plasma generated by the SSRR. In a voltage range between -60 V and 60 V, the fused stubs exhibited the expected behavior of spherical Langmuir probes and will be considered for future integration.

    Nyckelord
    Langmuir probe; bond wire; fusing; microplasma source
    Nationell ämneskategori
    Fysik Teknik och teknologier
    Forskningsämne
    Teknisk fysik med inriktning mot mikrosystemteknik
    Identifikatorer
    urn:nbn:se:uu:diva-251306 (URN)10.1088/0960-1317/25/10/105012 (DOI)000366827400028 ()
    Forskningsfinansiär
    RymdstyrelsenKnut och Alice Wallenbergs Stiftelse
    Tillgänglig från: 2015-04-15 Skapad: 2015-04-15 Senast uppdaterad: 2018-08-03Bibliografiskt granskad
  • 29.
    Berglund, Martin
    et al.
    Uppsala universitet, Teknisk-naturvetenskapliga vetenskapsområdet, Tekniska sektionen, Institutionen för teknikvetenskaper, Mikrosystemteknik.
    Gruden, Mathias
    Uppsala universitet, Teknisk-naturvetenskapliga vetenskapsområdet, Tekniska sektionen, Institutionen för teknikvetenskaper, Fasta tillståndets elektronik.
    Thornell, Greger
    Uppsala universitet, Teknisk-naturvetenskapliga vetenskapsområdet, Tekniska sektionen, Institutionen för teknikvetenskaper, Mikrosystemteknik.
    Persson, Anders
    Uppsala universitet, Teknisk-naturvetenskapliga vetenskapsområdet, Fysiska sektionen, Institutionen för fysik och astronomi, Tillämpad kärnfysik. Uppsala universitet, Teknisk-naturvetenskapliga vetenskapsområdet, Tekniska sektionen, Institutionen för teknikvetenskaper, Mikrosystemteknik.
    Evaluation of a microplasma source based on a stripline split-ring resonator2013Ingår i: Plasma sources science & technology (Print), ISSN 0963-0252, E-ISSN 1361-6595, Vol. 22, nr 5, s. 055017-Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    In this paper, a stripline split-ring resonator microwave-induced plasma source, aimed for integration in complex systems, is presented and compared with a traditional microstrip design. Devices based on the two designs are evaluated using a plasma breakdown test setup for measuring the power required to ignite plasmas at different pressures. Moreover, the radiation efficiency of the devices is investigated with a Wheeler cap, and their electromagnetic compatibility is investigated in a variable electrical environment emulating an application. Finally, the basic properties of the plasma in the two designs are investigated in terms of electron temperature, plasma potential and ion density. The study shows that, with a minor increase in plasma ignition power, the stripline design provides a more isolated and easy-to-integrate alternative to the conventional microstrip design. Moreover, the stripline devices showed a decreased antenna efficiency as compared with their microstrip counterparts, which is beneficial for plasma sources. Furthermore, the investigated stripline devices exhibited virtually no frequency shift in a varying electromagnetic environment, whereas the resonance frequency of their microstrip counterparts shifted up to 17.5%. With regard to the plasma parameters, the different designs showed only minor differences in electron temperature, whereas the ion density was higher with the stripline design.

  • 30.
    Berglund, Martin
    et al.
    Uppsala universitet, Teknisk-naturvetenskapliga vetenskapsområdet, Tekniska sektionen, Institutionen för teknikvetenskaper, Mikrosystemteknik, Ångström Space Technology Centre (ÅSTC).
    Khaji, Zahra
    Uppsala universitet, Teknisk-naturvetenskapliga vetenskapsområdet, Tekniska sektionen, Institutionen för teknikvetenskaper, Mikrosystemteknik, Ångström Space Technology Centre (ÅSTC).
    Klintberg, Lena
    Uppsala universitet, Teknisk-naturvetenskapliga vetenskapsområdet, Tekniska sektionen, Institutionen för teknikvetenskaper, Mikrosystemteknik.
    Persson, Anders
    Uppsala universitet, Teknisk-naturvetenskapliga vetenskapsområdet, Tekniska sektionen, Institutionen för teknikvetenskaper, Mikrosystemteknik, Ångström Space Technology Centre (ÅSTC).
    Sturesson, Peter
    Uppsala universitet, Teknisk-naturvetenskapliga vetenskapsområdet, Tekniska sektionen, Institutionen för teknikvetenskaper, Mikrosystemteknik, Ångström Space Technology Centre (ÅSTC).
    Söderberg Breivik, Johan
    Uppsala universitet, Teknisk-naturvetenskapliga vetenskapsområdet, Tekniska sektionen, Institutionen för teknikvetenskaper, Mikrosystemteknik, Ångström Space Technology Centre (ÅSTC).
    Thornell, Greger
    Uppsala universitet, Teknisk-naturvetenskapliga vetenskapsområdet, Tekniska sektionen, Institutionen för teknikvetenskaper, Mikrosystemteknik, Ångström Space Technology Centre (ÅSTC).
    Extreme-temperature lab on a chip for optogalvanic spectroscopy of ultra small samples – key components and a first integration attempt2016Ingår i: Journal of Physics: Conference Series, Institute of Physics (IOP), 2016Konferensbidrag (Refereegranskat)
    Abstract [en]

    This is a short summary of the authors’ recent R&D on valves, combustors, plasma sources, and pressure and temperature sensors, realized in high-temperature co-fired ceramics, and an account for the first attempt to monolithically integrate them to form a lab on a chip for sample administration, preparation and analysis, as a stage in optogalvanic spectroscopy.

  • 31.
    Berglund, Martin
    et al.
    Uppsala universitet, Teknisk-naturvetenskapliga vetenskapsområdet, Tekniska sektionen, Institutionen för teknikvetenskaper, Mikrosystemteknik.
    Palmer, Kristoffer
    Uppsala universitet, Teknisk-naturvetenskapliga vetenskapsområdet, Tekniska sektionen, Institutionen för teknikvetenskaper, Mikrosystemteknik.
    Lotfi, Sara
    Uppsala universitet, Teknisk-naturvetenskapliga vetenskapsområdet, Tekniska sektionen, Institutionen för teknikvetenskaper, Fasta tillståndets elektronik.
    Kratz, Henrik
    Uppsala universitet, Teknisk-naturvetenskapliga vetenskapsområdet, Tekniska sektionen, Institutionen för teknikvetenskaper, Mikrosystemteknik.
    Thornell, Greger
    Uppsala universitet, Teknisk-naturvetenskapliga vetenskapsområdet, Tekniska sektionen, Institutionen för teknikvetenskaper, Mikrosystemteknik.
    Dynamic characterization and modelling of a dual-axis beam steering device for performance understanding, optimization, and control design2013Ingår i: Journal of Micromechanics and Microengineering, ISSN 0960-1317, E-ISSN 1361-6439, Vol. 23, nr 4, s. 045020-Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    This paper presents a lumped thermal model of a dual-axis laser micromirror device for beam steering in a free-space optical (FSO) communication system, designed for fractionated spacecraft. An FSO communication system provides several advantages, such as larger bandwidth, smaller size and weight of the communication payload and less power consumption. A dual-axis mirror device is designed and realized using microelectromechanical systems technology. The fabrication is based on a double-sided, bulk micromachining process, where the mirror actuates thermally by joints consisting of v-grooves filled with the SU-8 polymer. The size of the device, consisting of a mirror, which is deflectable versus its frame in one direction, and through deflection of the frame in the other, is 15.4 × 10.4 × 0.3 mm3. In order to further characterize and understand the micromirror device, a Simulink state-space model of the actuator is set up using thermal and mechanical properties from a realized actuator. A deviation of less than 2% between the modelled and measured devices was obtained in an actuating temperature range of 20–200 °C. The model of the physical device was examined by evaluating its performance in vacuum, and by changing physical parameters, such as thickness and material composition. By this, design parameters were evaluated for performance gain and usability. For example, the crosstalk between the two actuators deflecting the mirror along its two axes in atmospheric pressure is projected to go down from 97% to 6% when changing the frame material from silicon to silicon dioxide. A feedback control system was also designed around the model in order to examine the possibility to make a robust control system for the physical device. In conclusion, the model of the actuator presented in this paper can be used for further understanding and development of the actuator system.

  • 32.
    Berglund, Martin
    et al.
    Uppsala universitet, Teknisk-naturvetenskapliga vetenskapsområdet, Tekniska sektionen, Institutionen för teknikvetenskaper, Mikrosystemteknik.
    Persson, Anders
    Uppsala universitet, Teknisk-naturvetenskapliga vetenskapsområdet, Fysiska sektionen, Institutionen för fysik och astronomi.
    Kratz, Henrik
    Uppsala universitet, Teknisk-naturvetenskapliga vetenskapsområdet, Tekniska sektionen, Institutionen för teknikvetenskaper, Mikrosystemteknik.
    Thornell, Greger
    Uppsala universitet, Teknisk-naturvetenskapliga vetenskapsområdet, Tekniska sektionen, Institutionen för teknikvetenskaper, Mikrosystemteknik.
    Microfluidics integrable plasma source powered by a silicon through-substrate split-ring resonator2013Ingår i: Solid-State Sensors, Actuators and Microsystems (TRANSDUCERS EUROSENSORS XXVII), 2013, s. 2608-2611Konferensbidrag (Övrigt vetenskapligt)
    Abstract [en]

    A novel microplasma source, based on a microstrip split-ring resonator design with electrodes integrated in its silicon substrate, was designed, manufactured and evaluated. This device should offer straightforward integration with other MEMS components, and has a plasma discharge gap with a controlled volume and geometry, with potential for microfluidics. Two realized devices were resonant at around 2.9 GHz with quality factors of 26.6 and 18.7. Two different plasma ignition modes were observed, where the plasma at low pressures was not confined to the gap but rather appeared between the ends of the electrodes on the backside.

  • 33.
    Berglund, Martin
    et al.
    Uppsala universitet, Teknisk-naturvetenskapliga vetenskapsområdet, Tekniska sektionen, Institutionen för teknikvetenskaper, Mikrosystemteknik.
    Persson, Anders
    Uppsala universitet, Teknisk-naturvetenskapliga vetenskapsområdet, Tekniska sektionen, Institutionen för teknikvetenskaper, Mikrosystemteknik.
    Thornell, Greger
    Uppsala universitet, Teknisk-naturvetenskapliga vetenskapsområdet, Tekniska sektionen, Institutionen för teknikvetenskaper, Mikrosystemteknik.
    A High-Performance Microplasma Source for Highly Sensitive and Robust Gas Analysis2014Ingår i: Proc. of Micronano System Workshop 2014, Uppsala, Sweden, May 15-16, 2014, 2014Konferensbidrag (Övrigt vetenskapligt)
  • 34.
    Berglund, Martin
    et al.
    Uppsala universitet, Teknisk-naturvetenskapliga vetenskapsområdet, Tekniska sektionen, Institutionen för teknikvetenskaper, Mikrosystemteknik.
    Persson, Anders
    Uppsala universitet, Teknisk-naturvetenskapliga vetenskapsområdet, Tekniska sektionen, Institutionen för teknikvetenskaper, Mikrosystemteknik.
    Thornell, Greger
    Uppsala universitet, Teknisk-naturvetenskapliga vetenskapsområdet, Tekniska sektionen, Institutionen för teknikvetenskaper, Mikrosystemteknik.
    Evaluation of dielectric properties of HTCC alumina for realization of plasma sources2015Ingår i: Journal of Electronic Materials, ISSN 0361-5235, E-ISSN 1543-186X, Vol. 44, nr 10, s. 3654-3660Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    As the sensitivity of optogalvanic spectroscopy based on prototype microplasma sources increases, contamination from composite materials in the printed circuit board used starts to become a concern. In this paper, a transfer to high-temperature cofired alumina and platinum is made and evaluated. The high-purity alumina provides an inert plasma environment, and allows for temperatures above 1000A degrees C, which is beneficial for future integration of a combustor. To facilitate the design of high-end plasma sources, characterization of the radio frequency (RF) parameters of the materials around 2.6 GHz is carried out. A RF resonator structure was fabricated in both microstrip and stripline configurations. These resonators were geometrically and electrically characterized, and epsilon (r) and tan were calculated using the RF waveguide design tool Wcalc. The resulting epsilon (r) for the microstrip and stripline was found to be 10.68 (+/- 0.12) and 9.65 (+/- 0.14), respectively. The average tan of all devices was found to be 0.0011 (+/- 0.0007). With these parameters, a series of proof-of-concept plasma sources were fabricated and evaluated. Some problems in the fabrication stemmed from the lamination and difficulties with the screen-printing, but a functioning plasma source was demonstrated.

  • 35.
    Berglund, Martin
    et al.
    Uppsala universitet, Teknisk-naturvetenskapliga vetenskapsområdet, Tekniska sektionen, Institutionen för teknikvetenskaper, Mikrosystemteknik.
    Sturesson, Peter
    Uppsala universitet, Teknisk-naturvetenskapliga vetenskapsområdet, Tekniska sektionen, Institutionen för teknikvetenskaper, Mikrosystemteknik. Swedish Defence University.
    Thornell, Greger
    Uppsala universitet, Teknisk-naturvetenskapliga vetenskapsområdet, Tekniska sektionen, Institutionen för teknikvetenskaper, Mikrosystemteknik.
    Persson, Anders
    Uppsala universitet, Teknisk-naturvetenskapliga vetenskapsområdet, Tekniska sektionen, Institutionen för teknikvetenskaper, Mikrosystemteknik.
    Manufacturing Miniature Langmuir probes by Fusing Platinum Bond Wires2015Ingår i: Journal of Micromechanics and Microengineering, ISSN 0960-1317, E-ISSN 1361-6439, Vol. 25, nr 10, artikel-id 105012Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    This paper reports on a novel method for manufacturing microscopic Langmuir probes with spherical tips from platinum bond wires for plasma characterization in microplasma sources by fusing. Here, the resulting endpoints, formed by droplets of a fused wire, are intended to act as a spherical Langmuir probe. For studying the fusing behavior, bond wires were wedge-bonded over a 2 mm wide slit, to emulate the final application, and fused at different currents and voltages. For electrical isolation, a set of wires were coated with a 4 µm thick layer of Parylene before they were fused. After fusing, the gap size, as well as the shape and area of the ends of the remaining stubs were measured. The yield of the process was also investigated, and the fusing event was studied using a high-speed camera for analyzing the dynamics of fusing. Four characteristic tip shapes were observed: spherical, semi-spherical, serpentine shaped and folded. The stub length leveled out at ~420µm. The fusing of the coated wires required a higher power for attaining a spherical shape. Finally, a Parylene coated bond wire was integrated into a stripline split-ring resonator (SSRR) microplasma source, and fused to form two Langmuir probes with spherical endpoints. These probes were used for measuring the I-V characteristics of a plasma generated by the SSRR. In a voltage range between -60 V and 60 V, the fused stubs exhibited the expected behavior of spherical Langmuir probes and will be considered for future integration.

  • 36.
    Berglund, Martin
    et al.
    Uppsala universitet, Teknisk-naturvetenskapliga vetenskapsområdet, Tekniska sektionen, Institutionen för teknikvetenskaper, Mikrosystemteknik.
    Thornell, Greger
    Uppsala universitet, Teknisk-naturvetenskapliga vetenskapsområdet, Tekniska sektionen, Institutionen för teknikvetenskaper, Mikrosystemteknik.
    Persson, Anders
    Uppsala universitet, Teknisk-naturvetenskapliga vetenskapsområdet, Fysiska sektionen, Institutionen för fysik och astronomi. Uppsala universitet, Teknisk-naturvetenskapliga vetenskapsområdet, Tekniska sektionen, Institutionen för teknikvetenskaper, Mikrosystemteknik.
    Microplasma source for optogalvanic spectroscopy of nanogram samples2013Ingår i: Journal of Applied Physics, ISSN 0021-8979, E-ISSN 1089-7550, Vol. 114, nr 3, s. 033302-Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    The demand for analysis of smaller samples in isotopic ratio measurements of rare isotopes is continuously rising with the development of new applications, particularly in biomedicine. Interesting in this aspect are methods based on optogalvanic spectroscopy, which have been reported to facilitate both 13C-to-12C and 14C-to-12C ratio measurements with high sensitivity. These methods also facilitate analysis of very small samples, down to the microgram range, which makes them very competitive to other technologies, e.g., accelerator mass spectroscopy. However, there exists a demand for moving beyond the microgram range, especially from regenerative medicine, where samples consist of, e.g., DNA, and, hence, the total sample amount is extremely small. Making optogalvanic spectroscopy of carbon isotopes applicable to such small samples, requires miniaturization of the key component of the system, namely the plasma source, in which the sample is ionized before analysis. In this paper, a novel design of such a microplasma source based on a stripline split-ring resonator is presented and evaluated in a basic optogalvanic spectrometer. The investigations focus on the capability of the plasma source to measure the optogalvanic signal in general, and the effect of different system and device specific parameters on the amplitude and stability of the optogalvanic signal in particular. Different sources of noise and instabilities are identified, and methods of mitigating these issues are discussed. Finally, the ability of the cell to handle analysis of samples down to the nanogram range is investigated, pinpointing the great prospects of stripline split-ring resonators in optogalvanic spectroscopy.

  • 37.
    Bergman, Henrik Dan
    Uppsala universitet, Teknisk-naturvetenskapliga vetenskapsområdet, Tekniska sektionen, Institutionen för teknikvetenskaper, Mikrosystemteknik.
    Increasing the Writing Resolution for Electro-hydrodynamic 3D-Printing: by Active Steering of e-jet2019Självständigt arbete på avancerad nivå (yrkesexamen), 20 poäng / 30 hpStudentuppsats (Examensarbete)
    Abstract [en]

    Additive manufacturing has grown considerably during the last couple of decades, whether it comes to the printing of metal structure or living cells. Additive manufacturing techniques relays on the successive addition of material to create the wanted structure. Among the diversity of these many printing techniques, electrohydrodynamic 3D-printing is of particular interest, as the technique has a promising outlook for high-resolution printing on the microscale. The technique is compatible with a myriad of thermoplastics, but its writing resolution is limited due to the inherent affect the manufacturing process has on the material. Electrostatic forces between already deposited fibres and the fibre in light affect the final position of printed fibre. This thesis evaluates the possibility to increase the writing resolution in melt electrohydrodynamic 3D printing by a closed-loop feedback system. Components were built and added to an already existing printing setup to implement in-situ measurements of the fibres position as well as active electrostatic guiding of the fibre. The setup consisted of a camera that determined the position of the fibre; the position was then used in a PID controller to calculate an appropriate potential. The potential was forwarded to a high voltage amplifier, connected to a steering electrode, mounted in the vicinity of the jet. The setup built for one-dimensional steering of the fibre improved the printing accuracy by ten times through suppressing the repulsive/attractive forces, where the process variable of the PID controller was measured. However, the precision decreased roughly four times as it was deposited on the substrate. The limitations of the system have been evaluated, and possible improvements for the two-dimensional control of the fibre are further discussed.

  • 38.
    Björnander Rahimi, Klara
    Uppsala universitet, Teknisk-naturvetenskapliga vetenskapsområdet, Tekniska sektionen, Institutionen för teknikvetenskaper, Mikrosystemteknik.
    Enrichment of microparticles in droplets using acoustophoresis2018Självständigt arbete på avancerad nivå (yrkesexamen), 20 poäng / 30 hpStudentuppsats (Examensarbete)
    Abstract [en]

    Acoustophoresis is a label free method where the acoustic radiation force is used to manipulate microparticles inside microfluidic channels. The magnitude of the force is dependent of several parameters, which include the density, speed of sound and size of the microparticles, as well as the amplitude of the pressure waves. Recently, acoustophoresis has been used in microfluidics to manipulate microparticles inside moving droplets. In this Master's thesis project, two microfluidic chip designs are used to enrich droplets with polystyrene beads (10 μm in diameter) using acoustophoresis. The microchips have been fabricated with two different fabrication methods; crystalline dependent wet etching and crystalline independent dry etching. In the microchips, water droplets in oil are generated with microparticles suspended in them. By using a channel width that is half a wavelength of the incoming acoustic waves, pressure nodal lines are created in the middle of the channel in which the microparticles align. The droplets then enters a droplet splitting feature, where they are divided into three daughter droplets. Since the majority of the incoming particles are recovered in the center daughter droplet while some of the droplet volume is removed, the center droplet is enriched with the microparticles. For the wet etched design stable droplet splitting was observed when the volumetric flow was 18 μL/min and the incoming droplets had a length-to-width ratio larger than 3. The maximum recovery for this design was 81.1% ± 13.8% with an applied voltage at 10 Vpp. Stable droplet splitting was observed for the dry etched chip at 10.5 μL/min and 18 μL/min at 10 and 20 Vpp, when the incoming droplet had a length-to-width ratio of 3. In this chip the maximum recovery was 93.2% ± 8.3% at the volumetric flow of 10.5 μL/min and an applied voltage of 20 Vpp.

  • 39.
    Blasi Romero, Anna
    et al.
    Uppsala universitet, Teknisk-naturvetenskapliga vetenskapsområdet, Tekniska sektionen, Institutionen för teknikvetenskaper, Nanoteknologi och funktionella material. Uppsala universitet, Science for Life Laboratory, SciLifeLab.
    Nguyen, Hugo
    Uppsala universitet, Teknisk-naturvetenskapliga vetenskapsområdet, Tekniska sektionen, Institutionen för teknikvetenskaper, Mikrosystemteknik.
    Barbe, Laurent
    Uppsala universitet, Teknisk-naturvetenskapliga vetenskapsområdet, Tekniska sektionen, Institutionen för teknikvetenskaper, Mikrosystemteknik. Uppsala universitet, Science for Life Laboratory, SciLifeLab.
    Tenje, Maria
    Uppsala universitet, Teknisk-naturvetenskapliga vetenskapsområdet, Tekniska sektionen, Institutionen för teknikvetenskaper, Mikrosystemteknik. Uppsala universitet, Science for Life Laboratory, SciLifeLab.
    Mestres, Gemma
    Uppsala universitet, Teknisk-naturvetenskapliga vetenskapsområdet, Tekniska sektionen, Institutionen för teknikvetenskaper, Mikrosystemteknik. Uppsala universitet, Science for Life Laboratory, SciLifeLab.
    Development and validation of a reusable microfluidic system for the evaluation of biomaterials’ biological properties2019Konferensbidrag (Övrigt vetenskapligt)
  • 40.
    Blomqvist, Mikael
    Uppsala universitet, Teknisk-naturvetenskapliga vetenskapsområdet, Tekniska sektionen, Institutionen för teknikvetenskaper, Mikrosystemteknik, Ångström Space Technology Centre (ÅSTC).
    Construction and evaluation of a magnetoresistive ground penetrating radar system2011Självständigt arbete på avancerad nivå (yrkesexamen), 20 poäng / 30 hpStudentuppsats (Examensarbete)
    Abstract [en]

    This Master Thesis examines the possibility to apply a magnetometer developed by the Ångstöm space technology center to a small magnetic ground penetrating radar system with dimension in the order of one dm³. The magnetometer is broadband (DC-1GHz) and miniaturized. Loop antennas are used to transmit the signal.

       A series of experiments have been performed in order to characterize the system, mainly examining the ability to determine distance to a target, using continuous sine wave signals and pulse trains. Standing wave patterns are formed between antenna and target and can be used for determining distance in the continuous case. When using a pulse train, the echo from the target could not be resolved using the current experiment set up, distance could therefore not be determined.

  • 41.
    Boden, Roger
    et al.
    Uppsala universitet, Teknisk-naturvetenskapliga vetenskapsområdet, Tekniska sektionen, Institutionen för teknikvetenskaper, Mikrosystemteknik. Materialvetenskap.
    Simu, U.
    Margell, J.
    Lehto, Marcus
    Uppsala universitet, Teknisk-naturvetenskapliga vetenskapsområdet, Tekniska sektionen, Institutionen för teknikvetenskaper, Materialvetenskap. Materialvetenskap.
    Hjort, Klas
    Uppsala universitet, Teknisk-naturvetenskapliga vetenskapsområdet, Tekniska sektionen, Institutionen för teknikvetenskaper, Mikrosystemteknik. Materialvetenskap.
    Thornell, Greger
    Uppsala universitet, Teknisk-naturvetenskapliga vetenskapsområdet, Tekniska sektionen, Institutionen för teknikvetenskaper, Mikrosystemteknik. Materialvetenskap.
    Schweitz, Jan-Åke
    Uppsala universitet, Teknisk-naturvetenskapliga vetenskapsområdet, Tekniska sektionen, Institutionen för teknikvetenskaper, Mikrosystemteknik. Materialvetenskap.
    Metallic high-pressure microfluidicpump with active valves2007Konferensbidrag (Refereegranskat)
  • 42.
    Bodén, Roger
    et al.
    Uppsala universitet, Teknisk-naturvetenskapliga vetenskapsområdet, Tekniska sektionen, Institutionen för teknikvetenskaper, Mikrosystemteknik.
    Hjort, Klas
    Uppsala universitet, Teknisk-naturvetenskapliga vetenskapsområdet, Tekniska sektionen, Institutionen för teknikvetenskaper, Mikrosystemteknik.
    Schweitz, Jan-Åke
    Uppsala universitet, Teknisk-naturvetenskapliga vetenskapsområdet, Tekniska sektionen, Institutionen för teknikvetenskaper, Mikrosystemteknik.
    Simu, Urban
    Uppsala universitet, Teknisk-naturvetenskapliga vetenskapsområdet, Tekniska sektionen, Institutionen för teknikvetenskaper, Mikrosystemteknik.
    A metallic micropump for high-pressure microfluidics2008Ingår i: Journal of Micromechanics and Microengineering, ISSN 0960-1317, E-ISSN 1361-6439, Vol. 18, nr 11, s. 115009-Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    This paper presents one of the strongest mechanical sub-cm(3) sized micropumps for microfluidics. It consists of two active valves and one pumping chamber, each operated by a paraffin actuator that is driven by a low-voltage square pulse waveform. The pump is fabricated in a simple process using parylene-coated stainless steel stencils, paraffin and copper clad polyimide. When driving the pump at 0.07 Hz and 2.0 V (0.8 W) per actuator, it pumped water without leakage at a flow rate of 0.75 mu L min(-1) up to above 50 bar (5 MPa) back-pressure. The frequency dependence was evaluated and a maximum flow rate of 1 mu L min(-1) at 0.21 Hz and 1.8 V was observed. A thermomechanical FEM analysis, which was in good agreement with experiments at low frequencies, predicts the behaviour at higher frequencies.

  • 43.
    Bodén, Roger
    et al.
    Uppsala universitet, Teknisk-naturvetenskapliga vetenskapsområdet, Tekniska sektionen, Institutionen för teknikvetenskaper, Mikrosystemteknik.
    Hjort, Klas
    Uppsala universitet, Teknisk-naturvetenskapliga vetenskapsområdet, Tekniska sektionen, Institutionen för teknikvetenskaper, Mikrosystemteknik.
    Simu, Urban
    Schweitz, Jan-Åke
    Uppsala universitet, Teknisk-naturvetenskapliga vetenskapsområdet, Tekniska sektionen, Institutionen för teknikvetenskaper, Mikrosystemteknik.
    Metallic high-pressure microfluidic pump2008Ingår i: MSW08, 2008, s. 29-Konferensbidrag (Refereegranskat)
  • 44.
    Bodén, Roger
    et al.
    Uppsala universitet, Teknisk-naturvetenskapliga vetenskapsområdet, Tekniska sektionen, Institutionen för teknikvetenskaper, Materialvetenskap.
    Lehto, Marcus
    Uppsala universitet, Teknisk-naturvetenskapliga vetenskapsområdet, Tekniska sektionen, Institutionen för teknikvetenskaper, Materialvetenskap.
    Simu, Urban
    Thornell, Greger
    Uppsala universitet, Teknisk-naturvetenskapliga vetenskapsområdet, Tekniska sektionen, Institutionen för teknikvetenskaper, Mikrosystemteknik.
    Hjort, Klas
    Uppsala universitet, Teknisk-naturvetenskapliga vetenskapsområdet, Tekniska sektionen, Institutionen för teknikvetenskaper, Mikrosystemteknik.
    Schweitz, Jan-Åke
    Uppsala universitet, Teknisk-naturvetenskapliga vetenskapsområdet, Tekniska sektionen, Institutionen för teknikvetenskaper, Materialvetenskap.
    A polymeric paraffin actuated high-pressure micropump2006Ingår i: Sensors and Actuators A, ISSN 0924-4247, Vol. 127, nr 1, s. 88-93Artikel i tidskrift (Refereegranskat)
  • 45.
    Bodén, Roger
    et al.
    Uppsala universitet, Teknisk-naturvetenskapliga vetenskapsområdet, Tekniska sektionen, Institutionen för teknikvetenskaper, Materialvetenskap.
    Lehto, Marcus
    Uppsala universitet, Teknisk-naturvetenskapliga vetenskapsområdet, Tekniska sektionen, Institutionen för teknikvetenskaper, Materialvetenskap.
    Simu, Urban
    Uppsala universitet, Teknisk-naturvetenskapliga vetenskapsområdet, Tekniska sektionen, Institutionen för teknikvetenskaper, Materialvetenskap.
    Thornell, Greger
    Uppsala universitet, Teknisk-naturvetenskapliga vetenskapsområdet, Tekniska sektionen, Institutionen för teknikvetenskaper, Materialvetenskap.
    Hjort, Klas
    Uppsala universitet, Teknisk-naturvetenskapliga vetenskapsområdet, Tekniska sektionen, Institutionen för teknikvetenskaper, Mikrosystemteknik.
    Schweitz, Jan-Åke
    Uppsala universitet, Teknisk-naturvetenskapliga vetenskapsområdet, Tekniska sektionen, Institutionen för teknikvetenskaper, Materialvetenskap.
    A polymeric paraffin actuated high-pressure micropump2006Ingår i: Sensors and Actuators A: Physical, ISSN 0924-4247, Vol. 127, nr 1, s. 88-93Artikel i tidskrift (Refereegranskat)
  • 46.
    Bodén, Roger
    et al.
    Uppsala universitet, Teknisk-naturvetenskapliga vetenskapsområdet, Tekniska sektionen, Institutionen för teknikvetenskaper, Materialvetenskap.
    Lehto, Marcus
    Uppsala universitet, Teknisk-naturvetenskapliga vetenskapsområdet, Tekniska sektionen, Institutionen för teknikvetenskaper, Materialvetenskap.
    Simu, Urban
    Uppsala universitet, Teknisk-naturvetenskapliga vetenskapsområdet, Tekniska sektionen, Institutionen för teknikvetenskaper, Materialvetenskap.
    Thornell, Greger
    Uppsala universitet, Teknisk-naturvetenskapliga vetenskapsområdet, Tekniska sektionen, Institutionen för teknikvetenskaper, Materialvetenskap.
    Hjort, Klas
    Uppsala universitet, Teknisk-naturvetenskapliga vetenskapsområdet, Tekniska sektionen, Institutionen för teknikvetenskaper, Mikrosystemteknik.
    Schweitz, Jan-Åke
    Uppsala universitet, Teknisk-naturvetenskapliga vetenskapsområdet, Tekniska sektionen, Institutionen för teknikvetenskaper, Materialvetenskap.
    A polymeric paraffin actuated high-pressure micropump2006Ingår i: Sensors and Actuators A-Physical, ISSN 0924-4247, E-ISSN 1873-3069, Vol. 127, nr 1, s. 88-93Artikel i tidskrift (Refereegranskat)
  • 47.
    Bodén, Roger
    et al.
    Uppsala universitet, Teknisk-naturvetenskapliga vetenskapsområdet, Tekniska sektionen, Institutionen för teknikvetenskaper, Mikrosystemteknik.
    Ogden, Sam
    Uppsala universitet, Teknisk-naturvetenskapliga vetenskapsområdet, Tekniska sektionen, Institutionen för teknikvetenskaper, Mikrosystemteknik.
    Hjort, Klas
    Uppsala universitet, Teknisk-naturvetenskapliga vetenskapsområdet, Tekniska sektionen, Institutionen för teknikvetenskaper, Mikrosystemteknik.
    Microdispenser with continuous flow and selectable target volume for microfluidic high-pressure applications2014Ingår i: Journal of microelectromechanical systems, ISSN 1057-7157, E-ISSN 1941-0158, Vol. 23, nr 2, s. 452-458Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    This paper presents a reusable microdispenser intended for continuous flow dispensing of variable and controlled volumes of liquid against high back-pressures. The microdispenser consists of two active valves and a dispenser chamber, all actuated by the volume change associated with the solid-to-liquid phase transition of paraffin wax. It is fabricated using stainless steel sheets, a flexible printed circuit board, and a polyimide membrane. All are covered with Parylene C for insulation and fusion bonding at assembly. A finite element method (FEM) model of the paraffin actuator is used to predict the resulting flow characteristics. The results show dispensing of well-defined volumes of 350 and 540 nL, with a good repeatability between dispensing sequences, as well as reproducibility between devices. In addition, the flow characteristics show no back-pressure dependence of the dispensed flow in the interval 0.5--2.0 MPa. The FEM model can be used to predict the flow characteristics qualitatively

  • 48.
    Brinnen, Mikael
    et al.
    Uppsala universitet, Teknisk-naturvetenskapliga vetenskapsområdet, Tekniska sektionen, Institutionen för teknikvetenskaper, Mikrosystemteknik.
    Laggar, Gustaf
    Uppsala universitet, Teknisk-naturvetenskapliga vetenskapsområdet, Tekniska sektionen, Institutionen för teknikvetenskaper, Mikrosystemteknik.
    New Cutting Tool Concept For Cylinder Boring2016Självständigt arbete på grundnivå (yrkesexamen), 10 poäng / 15 hpStudentuppsats (Examensarbete)
    Abstract [en]

    This thesis describes the process and result of generating concepts for a new adjustable cutting tool with integrated components. It was conducted under a period of ten weeks at the department R&D Digital Machining at Sandvik Coromant, Sandviken. The focus of the thesis was to generate and evaluate different concepts using well known methods such as TRIZ Contradiction and 40 principles, SCAMPER, Wish and Wonder, Brainstorming, Weight Determination matrix and Pugh matrix. 

    To catch up on the latest technologies and similar tools in the industry today a literature study was conducted which resulted in a requirement specification for the concept in accordance with expertise from Sandvik Coromant. The key problems to be solved were the demanding tolerances and precision together with high forces and the limited space in the tool body.  

    The thesis resulted in a selected concept with chosen components to meet the demanding requirements. The concept is presented in a 3D CAD-model with description and necessary data. The conclusion includes recommendations to Sandvik Coromant to further develop the selected concept into a prototype so that physical test can be performed and lifespan of electronic components can be evaluated. 

  • 49.
    Cantoni, Federico
    et al.
    Uppsala universitet, Teknisk-naturvetenskapliga vetenskapsområdet, Tekniska sektionen, Institutionen för teknikvetenskaper, Mikrosystemteknik.
    Hilborn, Jöns
    Uppsala universitet, Teknisk-naturvetenskapliga vetenskapsområdet, Kemiska sektionen, Institutionen för kemi - Ångström, Polymerkemi.
    Johansson, Sofia
    Uppsala universitet, Teknisk-naturvetenskapliga vetenskapsområdet, Tekniska sektionen, Institutionen för teknikvetenskaper, Mikrosystemteknik.
    Pohlit, Hannah
    Uppsala universitet, Teknisk-naturvetenskapliga vetenskapsområdet, Tekniska sektionen, Institutionen för teknikvetenskaper, Mikrosystemteknik. Uppsala universitet, Teknisk-naturvetenskapliga vetenskapsområdet, Kemiska sektionen, Institutionen för kemi - Ångström, Polymerkemi.
    Porras, Ana Maria
    Uppsala universitet, Teknisk-naturvetenskapliga vetenskapsområdet, Tekniska sektionen, Institutionen för teknikvetenskaper, Mikrosystemteknik.
    Samanta, Ayan
    Uppsala universitet, Teknisk-naturvetenskapliga vetenskapsområdet, Kemiska sektionen, Institutionen för kemi - Ångström, Polymerkemi.
    Tenje, Maria
    Uppsala universitet, Teknisk-naturvetenskapliga vetenskapsområdet, Tekniska sektionen, Institutionen för teknikvetenskaper, Mikrosystemteknik. Uppsala universitet, Science for Life Laboratory, SciLifeLab.
    2D and 3D patterning of biological hydrogels for organ-on-chip applications2018Konferensbidrag (Övrigt vetenskapligt)
  • 50.
    Carter, Sarah-Sophia
    et al.
    Uppsala universitet, Teknisk-naturvetenskapliga vetenskapsområdet, Tekniska sektionen, Institutionen för teknikvetenskaper, Mikrosystemteknik.
    Atif, Abdul
    Uppsala universitet, Teknisk-naturvetenskapliga vetenskapsområdet, Tekniska sektionen, Institutionen för teknikvetenskaper, Mikrosystemteknik.
    Lanekoff, Ingela
    Uppsala universitet, Teknisk-naturvetenskapliga vetenskapsområdet, Kemiska sektionen, Institutionen för kemi - BMC, Analytisk kemi.
    Tenje, Maria
    Uppsala universitet, Teknisk-naturvetenskapliga vetenskapsområdet, Tekniska sektionen, Institutionen för teknikvetenskaper, Mikrosystemteknik.
    Mestres, Gemma
    Uppsala universitet, Teknisk-naturvetenskapliga vetenskapsområdet, Tekniska sektionen, Institutionen för teknikvetenskaper, Mikrosystemteknik.
    Tailoring the biocompatibility of the elastomer PDMS for on-chip applications2018Konferensbidrag (Refereegranskat)
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