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  • 1.
    Afshar, Reza
    et al.
    Uppsala University, Disciplinary Domain of Science and Technology, Technology, Department of Engineering Sciences, Applied Mechanics.
    Alavyoon, Navid
    Uppsala University, Disciplinary Domain of Science and Technology, Technology, Department of Engineering Sciences, Microsystems Technology.
    Ahlgren, Anders
    Swedish National Maritime Museums, the Vasa Museum.
    van Dijk, Nico P.
    Uppsala University, Disciplinary Domain of Science and Technology, Technology, Department of Engineering Sciences, Applied Mechanics.
    Vorobyev, Alexey
    Uppsala University, Disciplinary Domain of Science and Technology, Technology, Department of Engineering Sciences, Applied Mechanics.
    Gamstedt, Kristofer
    Uppsala University, Disciplinary Domain of Science and Technology, Technology, Department of Engineering Sciences, Applied Mechanics.
    A full-scale finite-element model of the Vasa ship2017In: Proceedings of ECCOMAS Thematic Conference CompWood 2017: Computational Methods in Wood Mechanics, 2017Conference paper (Refereed)
    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 University, Disciplinary Domain of Science and Technology, Technology, Department of Engineering Sciences, Solid State Electronics.
    Seung, Hee Jeong
    Uppsala University, Disciplinary Domain of Science and Technology, Technology, Department of Engineering Sciences, Solid State Electronics.
    Jiao, Mingzhi
    Uppsala University, Disciplinary Domain of Science and Technology, Technology, Department of Engineering Sciences, Microsystems Technology.
    Wu, Zhigang
    Uppsala University, Disciplinary Domain of Science and Technology, Technology, Department of Engineering Sciences, Microsystems Technology.
    Zhang, Shi-Li
    Uppsala University, Disciplinary Domain of Science and Technology, Technology, Department of Engineering Sciences, Solid State Electronics.
    Zhang, Zhi-Bin
    Uppsala University, Disciplinary Domain of Science and Technology, Technology, Department of Engineering Sciences, Solid State Electronics.
    Graphene as a Diffusion Barrier in Galinstan-Solid Metal Contacts2014In: IEEE Transactions on Electron Devices, ISSN 0018-9383, E-ISSN 1557-9646, Vol. 61, no 8, p. 2996-3000Article in journal (Refereed)
    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. Ali, M.
    et al.
    Svensk, O.
    Zhen, Z.
    Suihkonen, S.
    Törmä, P. T.
    Lipsanen, H.
    Sopanen, M.
    Hjort, Klas
    Uppsala University, Disciplinary Domain of Science and Technology, Technology, Department of Engineering Sciences, Microsystems Technology.
    Jensen, Jens
    Uppsala University, Disciplinary Domain of Science and Technology, Technology, Department of Engineering Sciences, Ion Physics.
    Reduced photoluminescence from InGaN/GaN multiple quantum well structures following 40 MeV iodine ion irradiation2009In: Physica. B, Condensed matter, ISSN 0921-4526, E-ISSN 1873-2135, Vol. 404, no 23-24, p. 4925-4928Article in journal (Refereed)
    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.

  • 4.
    Almandoz-Gil, Leire
    et al.
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Public Health and Caring Sciences, Geriatrics.
    Welander, Hedvig
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Public Health and Caring Sciences, Geriatrics.
    Ihse, Elisabet
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Public Health and Caring Sciences, Geriatrics.
    Emami Khoonsari, Payam
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Medical Sciences, Cancer Pharmacology and Computational Medicine.
    Musunuri, Sravani
    Uppsala University, Disciplinary Domain of Science and Technology, Chemistry, Department of Chemistry - BMC, Analytical Chemistry. Uppsala University, Science for Life Laboratory, SciLifeLab.
    Lendel, Christofer
    KTH, Royal Institute of Technology, Sweden.
    Sigvardson, Jessica
    BioArctic AB, Sweden.
    Karlsson, Mikael
    Uppsala University, Disciplinary Domain of Science and Technology, Technology, Department of Engineering Sciences, Applied Materials Sciences. Uppsala University, Disciplinary Domain of Science and Technology, Technology, Department of Engineering Sciences, Microsystems Technology.
    Ingelsson, Martin
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Public Health and Caring Sciences, Geriatrics.
    Kultima, Kim
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Medical Sciences, Cancer Pharmacology and Computational Medicine.
    Bergström, Joakim
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Public Health and Caring Sciences, Geriatrics.
    Low molar excess of 4-oxo-2-nonenal and 4-hydroxy-2-nonenal promote oligomerization of alpha-synuclein through different pathways2017In: Free Radical Biology & Medicine, ISSN 0891-5849, E-ISSN 1873-4596, Vol. 110, p. 421-431Article in journal (Refereed)
  • 5.
    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 University, Disciplinary Domain of Science and Technology, Technology, Department of Engineering Sciences, Microsystems Technology. Uppsala University, 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 minispidroin2017In: Nature Chemical Biology, ISSN 1552-4450, E-ISSN 1552-4469, Vol. 13, no 3, p. 262-264Article in journal (Refereed)
    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.

  • 6.
    Andersson, Martin
    Uppsala University, Disciplinary Domain of Science and Technology, Technology, Department of Engineering Sciences, Microsystems Technology.
    Ag-In transient liquid phase bonding for high temperature stainless steel micro actuators2013Independent thesis Advanced level (professional degree), 20 credits / 30 HE creditsStudent thesis
    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.

  • 7.
    Andersson, Martin
    et al.
    Uppsala University, Disciplinary Domain of Science and Technology, Technology, Department of Engineering Sciences, Microsystems Technology.
    Ek, Johan
    Uppsala University, Disciplinary Domain of Science and Technology, Technology, Department of Engineering Sciences, Microsystems Technology.
    Hedman, Ludvig
    Uppsala University, Disciplinary Domain of Science and Technology, Technology, Department of Engineering Sciences, Microsystems Technology.
    Johansson, Fredrik
    Uppsala University, Disciplinary Domain of Science and Technology, Technology, Department of Engineering Sciences, Microsystems Technology.
    Sehlstedt, Viktor
    Uppsala University, Disciplinary Domain of Science and Technology, Technology, Department of Engineering Sciences, Microsystems Technology.
    Stocklassa, Jesper
    Uppsala University, Disciplinary Domain of Science and Technology, Technology, Department of Engineering Sciences, Microsystems Technology.
    Snögren, Pär
    Uppsala University, Disciplinary Domain of Science and Technology, Technology, Department of Engineering Sciences, Microsystems Technology.
    Pettersson, Victor
    Uppsala University, Disciplinary Domain of Science and Technology, Technology, Department of Engineering Sciences, Microsystems Technology.
    Larsson, Jonas
    Uppsala University, Disciplinary Domain of Science and Technology, Technology, Department of Engineering Sciences, Microsystems Technology.
    Vizuete, Olivier
    Uppsala University, Disciplinary Domain of Science and Technology, Technology, Department of Engineering Sciences, Microsystems Technology.
    Hjort, Klas
    Uppsala University, Disciplinary Domain of Science and Technology, Technology, Department of Engineering Sciences, Microsystems Technology.
    Klintberg, Lena
    Uppsala University, Disciplinary Domain of Science and Technology, Technology, Department of Engineering Sciences, Microsystems Technology.
    Thin film metal sensors in fusion bonded glass chips for high-pressure microfluidics2017In: Journal of Micromechanics and Microengineering, ISSN 0960-1317, E-ISSN 1361-6439, Vol. 27, no 1, article id 015018Article in journal (Refereed)
    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.

  • 8.
    Andersson, Martin
    et al.
    Uppsala University, Disciplinary Domain of Science and Technology, Technology, Department of Engineering Sciences, Microsystems Technology.
    Hjort, Klas
    Uppsala University, Disciplinary Domain of Science and Technology, Technology, Department of Engineering Sciences, Microsystems Technology.
    Klintberg, Lena
    Uppsala University, Disciplinary Domain of Science and Technology, Technology, Department of Engineering Sciences, Microsystems Technology.
    Fracture strength of glass chips for high-pressure microfluidics2016In: Journal of Micromechanics and Microengineering, ISSN 0960-1317, E-ISSN 1361-6439, Vol. 26, no 9, article id 095009Article in journal (Refereed)
    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.

  • 9.
    Andersson, Martin
    et al.
    Uppsala University, Disciplinary Domain of Science and Technology, Technology, Department of Engineering Sciences, Microsystems Technology.
    Hjort, Klas
    Uppsala University, Disciplinary Domain of Science and Technology, Technology, Department of Engineering Sciences, Microsystems Technology.
    Klintberg, Lena
    Uppsala University, Disciplinary Domain of Science and Technology, Technology, Department of Engineering Sciences, Microsystems Technology.
    High pressure glass microfluidics for supercritical CO2 with aqueous solutions2016Conference paper (Refereed)
    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.

  • 10.
    Andersson, Martin
    et al.
    Uppsala University, Disciplinary Domain of Science and Technology, Technology, Department of Engineering Sciences, Microsystems Technology.
    Hjort, Klas
    Uppsala University, Disciplinary Domain of Science and Technology, Technology, Department of Engineering Sciences, Microsystems Technology.
    Klintberg, Lena
    Uppsala University, Disciplinary Domain of Science and Technology, Technology, Department of Engineering Sciences, Microsystems Technology.
    High-Speed Imaging Of The ph Drop In Aqueous solutions In Contact With Supercritical Co2 Segments2016Conference paper (Other academic)
    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.

  • 11.
    Andersson, Martin
    et al.
    Uppsala University, Disciplinary Domain of Science and Technology, Technology, Department of Engineering Sciences, Microsystems Technology.
    Karolina, Svensson
    Uppsala University, Disciplinary Domain of Science and Technology, Technology, Department of Engineering Sciences, Microsystems Technology.
    Klintberg, Lena
    Uppsala University, Disciplinary Domain of Science and Technology, Technology, Department of Engineering Sciences, Microsystems Technology.
    Hjort, Klas
    Uppsala University, Disciplinary Domain of Science and Technology, Technology, Department of Engineering Sciences, Microsystems Technology.
    A microfluidic control board for high-pressure flow, composition, and relative permittivityIn: Article in journal (Refereed)
  • 12.
    Andersson, Martin
    et al.
    Uppsala University, Disciplinary Domain of Science and Technology, Technology, Department of Engineering Sciences, Microsystems Technology.
    Klintberg, Lena
    Uppsala University, Disciplinary Domain of Science and Technology, Technology, Department of Engineering Sciences, Microsystems Technology.
    Hjort, Klas
    Uppsala University, Disciplinary Domain of Science and Technology, Technology, Department of Engineering Sciences, Microsystems Technology.
    High Pressure Glass Devices For CO2 And H2O2016Conference paper (Other academic)
    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. 

  • 13.
    Andersson, Martin
    et al.
    Uppsala University, Disciplinary Domain of Science and Technology, Technology, Department of Engineering Sciences, Microsystems Technology.
    Klintberg, Lena
    Uppsala University, Disciplinary Domain of Science and Technology, Technology, Department of Engineering Sciences, Microsystems Technology.
    Svensson, karolina
    Uppsala University, Disciplinary Domain of Science and Technology, Technology, Department of Engineering Sciences, Microsystems Technology.
    Södergren, Simon
    Uppsala University, Disciplinary Domain of Science and Technology, Technology, Department of Engineering Sciences, Microsystems Technology.
    Hjort, Klas
    Uppsala University, Disciplinary Domain of Science and Technology, Technology, Department of Engineering Sciences, Microsystems Technology.
    Microfluidics for High-Pressure Analyses2018In: 12th Micronano System Workshop (MSW 2018, May 14-15, 2018, Espoo, Finland) / [ed] Samilu Fransilla, 2018, p. 8-8Conference paper (Other academic)
    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.

  • 14.
    Andersson, Martin
    et al.
    Uppsala University, Disciplinary Domain of Science and Technology, Technology, Department of Engineering Sciences, Microsystems Technology.
    Knaust, Stefan
    Uppsala University, Disciplinary Domain of Science and Technology, Technology, Department of Engineering Sciences, Microsystems Technology.
    Ogden, Sam
    Uppsala University, Disciplinary Domain of Science and Technology, Technology, Department of Engineering Sciences, Microsystems Technology.
    Hjort, Klas
    Uppsala University, Disciplinary Domain of Science and Technology, Technology, Department of Engineering Sciences, Microsystems Technology.
    Bodén, Roger
    Uppsala University, Disciplinary Domain of Science and Technology, Technology, Department of Engineering Sciences, Microsystems Technology.
    Integrated high-pressure fluid manipulation in microfluidic systems2014Conference paper (Other academic)
  • 15.
    Andersson, Martin
    et al.
    Uppsala University, Disciplinary Domain of Science and Technology, Technology, Department of Engineering Sciences, Microsystems Technology.
    Mårtensson, Gustaf
    EMSL, MC2, Chalmers University of Technology, Göteborg, Sweden.
    Klintberg, Lena
    Uppsala University, Disciplinary Domain of Science and Technology, Technology, Department of Engineering Sciences, Microsystems Technology.
    Flowing and pressurizing a solid-liquid two phase monodispersed fluid with high solid content in a transparent microfluidic high-pressure chip2017Conference paper (Refereed)
  • 16.
    Andersson, Martin
    et al.
    Uppsala University, Disciplinary Domain of Science and Technology, Technology, Department of Engineering Sciences, Microsystems Technology.
    Mårtensson, Gustav
    Mycronic AB, Täby.; Chalmers Univ Technol, MC2, EMSL, Gothenburg.
    Klintberg, Lena
    Uppsala University, Disciplinary Domain of Science and Technology, Technology, Department of Engineering Sciences, Microsystems Technology.
    Flowing and pressurizing a solid-liquid two phase monodispersed fluid with high solid content in a transparent microfluidic high-pressure chip2017In: 28TH MICROMECHANICS AND MICROSYSTEMS EUROPE WORKSHOP, IOP PUBLISHING LTD , 2017, article id UNSP 012010Conference paper (Refereed)
    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.

  • 17.
    Andersson, Martin
    et al.
    Uppsala University, Disciplinary Domain of Science and Technology, Technology, Department of Engineering Sciences, Microsystems Technology. Uppsala University, Disciplinary Domain of Science and Technology, Technology, Department of Engineering Sciences, Applied Materials Sciences.
    Rodriguez-Meizoso, Irene
    Turner, Charlotta
    Hjort, Klas
    Klintberg, Lena
    Uppsala University, Disciplinary Domain of Science and Technology, Technology, Department of Engineering Sciences, Microsystems Technology.
    Dynamic pH determination at high pressure of aqueous additive mixtures in contact with dense CO22018In: Journal of Supercritical Fluids, ISSN 0896-8446, E-ISSN 1872-8162, Vol. 136, p. 95-101Article in journal (Refereed)
    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.

  • 18.
    Andersson, Martin
    et al.
    Uppsala University, Disciplinary Domain of Science and Technology, Technology, Department of Engineering Sciences, Microsystems Technology.
    Stocklassa, Jesper
    Uppsala University, Disciplinary Domain of Science and Technology, Technology, Department of Engineering Sciences, Microsystems Technology.
    Klintberg, Lena
    Uppsala University, Disciplinary Domain of Science and Technology, Technology, Department of Engineering Sciences, Microsystems Technology.
    Hjort, Klas
    Uppsala University, Disciplinary Domain of Science and Technology, Technology, Department of Engineering Sciences, Microsystems Technology.
    Control Systems For Gas-Expanded Liquids In Microreactors2017Conference paper (Refereed)
  • 19.
    Andersson, Martin
    et al.
    Uppsala University, Disciplinary Domain of Science and Technology, Technology, Department of Engineering Sciences, Microsystems Technology.
    Wilson, Anton
    Uppsala University, Disciplinary Domain of Science and Technology, Technology, Department of Engineering Sciences, Microsystems Technology.
    Hjort, Klas
    Uppsala University, Disciplinary Domain of Science and Technology, Technology, Department of Engineering Sciences, Microsystems Technology.
    Klintberg, Lena
    Uppsala University, Disciplinary Domain of Science and Technology, Technology, Department of Engineering Sciences, Microsystems Technology.
    A microfluidic relative permittivity sensor for feedback control of carbon dioxide expanded liquid flowsIn: Article in journal (Refereed)
  • 20.
    Arbat, Anna
    et al.
    SIC, Departament d’Electrònica, Universitat de Barcelona, Barcelona, Spain.
    Edqvist, Erik
    Uppsala University, Disciplinary Domain of Science and Technology, Technology, Department of Engineering Sciences, Microsystems Technology.
    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 University, Disciplinary Domain of Science and Technology, Technology, Department of Engineering Sciences, Microsystems Technology.
    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-robot2009In: Sensors and Actuators A-Physical, ISSN 0924-4247, E-ISSN 1873-3069, Vol. 153, no 1, p. 76-83Article in journal (Refereed)
    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.

  • 21.
    Barkefors, Irmeli
    et al.
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Medical Biochemistry and Microbiology.
    Thorslund, Sara
    Uppsala University, Disciplinary Domain of Science and Technology, Technology, Department of Engineering Sciences, Microsystems Technology.
    Nikolajeff, Fredrik
    Uppsala University, Disciplinary Domain of Science and Technology, Technology, Department of Engineering Sciences, Microsystems Technology.
    Kreuger, Johan
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Medical Biochemistry and Microbiology.
    A fluidic device to study directional angiogenesis in complex tissue and organ culture models2009In: Lab on a Chip, ISSN 1473-0197, E-ISSN 1473-0189, Vol. 9, no 4, p. 529-535Article in journal (Refereed)
    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.

  • 22. Bejhed, Johan
    et al.
    Nguyen, Hugo
    Uppsala University, Disciplinary Domain of Science and Technology, Technology, Department of Engineering Sciences, Materials Science. Materialvetenskap.
    Åstrand, Peter
    Eriksson, Anders
    Uppsala University, Disciplinary Domain of Science and Technology, Technology, Department of Engineering Sciences, Microsystems Technology.
    Köhler, Johan
    Uppsala University, Disciplinary Domain of Science and Technology, Technology, Department of Engineering Sciences, Microsystems Technology.
    Numeric modeling and verification of crossed v-groove particle filters2006In: Journal of Michromechanics and MicroengineeringArticle in journal (Refereed)
  • 23.
    Berglund, Martin
    Uppsala University, Disciplinary Domain of Science and Technology, Technology, Department of Engineering Sciences, Microsystems Technology, Ångström Space Technology Centre (ÅSTC).
    Miniature Plasma Sources for High-Precision Molecular Spectroscopy in Planetary Exploration2015Doctoral thesis, comprehensive summary (Other academic)
    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.

    List of papers
    1. Operation characteristics and optical emission distribution of a miniaturized silicon through-substrate split-ring resonator microplasma source
    Open this publication in new window or tab >>Operation characteristics and optical emission distribution of a miniaturized silicon through-substrate split-ring resonator microplasma source
    2014 (English)In: Journal of microelectromechanical systems, ISSN 1057-7157, E-ISSN 1941-0158, Vol. 23, no 6, p. 1340-1345Article in journal (Refereed) 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.

    National Category
    Physical Sciences Engineering and Technology
    Identifiers
    urn:nbn:se:uu:diva-239111 (URN)10.1109/JMEMS.2014.2312849 (DOI)000345851100010 ()
    Available from: 2015-01-05 Created: 2014-12-18 Last updated: 2017-12-05Bibliographically approved
    2. Evaluation of a microplasma source based on a stripline split-ring resonator
    Open this publication in new window or tab >>Evaluation of a microplasma source based on a stripline split-ring resonator
    2013 (English)In: Plasma sources science & technology (Print), ISSN 0963-0252, E-ISSN 1361-6595, Vol. 22, no 5, p. 055017-Article in journal (Refereed) 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.

    Place, publisher, year, edition, pages
    Institute of Physics (IOP), 2013
    Keywords
    Split-ring resonator, Microwave plasma, Microstrip, Stripline, Plasma, Wheeler cap, Langmuir probe
    National Category
    Other Physics Topics Engineering and Technology
    Research subject
    Engineering Science with specialization in Microsystems Technology; Engineering Science with specialization in Microwave Technology
    Identifiers
    urn:nbn:se:uu:diva-206792 (URN)10.1088/0963-0252/22/5/055017 (DOI)000325246400017 ()
    Available from: 2013-09-04 Created: 2013-09-04 Last updated: 2017-12-06Bibliographically approved
    3. Microplasma source for optogalvanic spectroscopy of nanogram samples
    Open this publication in new window or tab >>Microplasma source for optogalvanic spectroscopy of nanogram samples
    2013 (English)In: Journal of Applied Physics, ISSN 0021-8979, E-ISSN 1089-7550, Vol. 114, no 3, p. 033302-Article in journal (Refereed) 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.

    Place, publisher, year, edition, pages
    American Institute of Physics (AIP), 2013
    Keywords
    nanostructured materials, optogalvanic spectroscopy, plasma instability, plasma probes, plasma sources, strip line resonators
    National Category
    Other Physics Topics Engineering and Technology
    Research subject
    Engineering Science with specialization in Microsystems Technology; Engineering Science with specialization in Ion Physics; Engineering Science with specialization in Microwave Technology
    Identifiers
    urn:nbn:se:uu:diva-204156 (URN)10.1063/1.4813414 (DOI)000322202700014 ()
    Available from: 2013-07-22 Created: 2013-07-22 Last updated: 2017-12-06Bibliographically approved
    4. Stripline split-ring resonator with integrated optogalvanic sample cell
    Open this publication in new window or tab >>Stripline split-ring resonator with integrated optogalvanic sample cell
    Show others...
    2014 (English)In: Laser Physics Letters, ISSN 1612-2011, Vol. 11, no 4, p. 045701-Article in journal, Letter (Refereed) 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.

    Place, publisher, year, edition, pages
    Institute of Physics (IOP), 2014
    Keywords
    Optogalvanic spectroscopy, Laser-assisted ratio analyzer, Split-ring resonator, microwave-induced microplasma source
    National Category
    Atom and Molecular Physics and Optics Fusion, Plasma and Space Physics Other Materials Engineering
    Research subject
    Physics; Engineering Science with specialization in Microsystems Technology
    Identifiers
    urn:nbn:se:uu:diva-218769 (URN)10.1088/1612-2011/11/4/045701 (DOI)000332768800011 ()
    Funder
    Swedish Research Council, A0442201
    Available from: 2014-02-17 Created: 2014-02-17 Last updated: 2015-05-12Bibliographically approved
    5. Improved optogalvanic detection with voltage biased Langmuir probes
    Open this publication in new window or tab >>Improved optogalvanic detection with voltage biased Langmuir probes
    2014 (English)In: Journal of Applied Physics, ISSN 0021-8979, E-ISSN 1089-7550, Vol. 116, no 24, p. 243301-Article in journal (Refereed) 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.

    National Category
    Physical Sciences
    Identifiers
    urn:nbn:se:uu:diva-242865 (URN)10.1063/1.4904964 (DOI)000347164300003 ()
    Available from: 2015-02-04 Created: 2015-02-02 Last updated: 2017-12-05Bibliographically approved
    6. Evaluation of dielectric properties of HTCC alumina for realization of plasma sources
    Open this publication in new window or tab >>Evaluation of dielectric properties of HTCC alumina for realization of plasma sources
    2015 (English)In: Journal of Electronic Materials, ISSN 0361-5235, E-ISSN 1543-186X, Vol. 44, no 10, p. 3654-3660Article in journal (Refereed) 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.

    National Category
    Ceramics Engineering and Technology Physical Sciences
    Research subject
    Engineering Science with specialization in Microsystems Technology
    Identifiers
    urn:nbn:se:uu:diva-251300 (URN)10.1007/s11664-015-3901-7 (DOI)000360672900061 ()
    Funder
    Swedish National Space BoardKnut and Alice Wallenberg Foundation
    Available from: 2015-04-15 Created: 2015-04-15 Last updated: 2017-12-04Bibliographically approved
    7. Manufacturing Miniature Langmuir probes by Fusing Platinum Bond Wires
    Open this publication in new window or tab >>Manufacturing Miniature Langmuir probes by Fusing Platinum Bond Wires
    2015 (English)In: Journal of Micromechanics and Microengineering, ISSN 0960-1317, E-ISSN 1361-6439, Vol. 25, no 10, article id 105012Article in journal (Refereed) 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.

    Keywords
    Langmuir probe; bond wire; fusing; microplasma source
    National Category
    Physical Sciences Engineering and Technology
    Research subject
    Engineering Science with specialization in Microsystems Technology
    Identifiers
    urn:nbn:se:uu:diva-251306 (URN)10.1088/0960-1317/25/10/105012 (DOI)000366827400028 ()
    Funder
    Swedish National Space BoardKnut and Alice Wallenberg Foundation
    Available from: 2015-04-15 Created: 2015-04-15 Last updated: 2017-12-04Bibliographically approved
  • 24.
    Berglund, Martin
    et al.
    Uppsala University, Disciplinary Domain of Science and Technology, Technology, Department of Engineering Sciences, Microsystems Technology.
    Gruden, Mathias
    Uppsala University, Disciplinary Domain of Science and Technology, Technology, Department of Engineering Sciences, Solid State Electronics.
    Thornell, Greger
    Uppsala University, Disciplinary Domain of Science and Technology, Technology, Department of Engineering Sciences, Microsystems Technology.
    Persson, Anders
    Uppsala University, Disciplinary Domain of Science and Technology, Physics, Department of Physics and Astronomy, Applied Nuclear Physics. Uppsala University, Disciplinary Domain of Science and Technology, Technology, Department of Engineering Sciences, Microsystems Technology.
    Evaluation of a microplasma source based on a stripline split-ring resonator2013In: Plasma sources science & technology (Print), ISSN 0963-0252, E-ISSN 1361-6595, Vol. 22, no 5, p. 055017-Article in journal (Refereed)
    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.

  • 25.
    Berglund, Martin
    et al.
    Uppsala University, Disciplinary Domain of Science and Technology, Technology, Department of Engineering Sciences, Microsystems Technology, Ångström Space Technology Centre (ÅSTC).
    Khaji, Zahra
    Uppsala University, Disciplinary Domain of Science and Technology, Technology, Department of Engineering Sciences, Microsystems Technology, Ångström Space Technology Centre (ÅSTC).
    Klintberg, Lena
    Uppsala University, Disciplinary Domain of Science and Technology, Technology, Department of Engineering Sciences, Microsystems Technology.
    Persson, Anders
    Uppsala University, Disciplinary Domain of Science and Technology, Technology, Department of Engineering Sciences, Microsystems Technology, Ångström Space Technology Centre (ÅSTC).
    Sturesson, Peter
    Uppsala University, Disciplinary Domain of Science and Technology, Technology, Department of Engineering Sciences, Microsystems Technology, Ångström Space Technology Centre (ÅSTC).
    Söderberg Breivik, Johan
    Uppsala University, Disciplinary Domain of Science and Technology, Technology, Department of Engineering Sciences, Microsystems Technology, Ångström Space Technology Centre (ÅSTC).
    Thornell, Greger
    Uppsala University, Disciplinary Domain of Science and Technology, Technology, Department of Engineering Sciences, Microsystems Technology, Ångström Space Technology Centre (ÅSTC).
    Extreme-temperature lab on a chip for optogalvanic spectroscopy of ultra small samples – key components and a first integration attempt2016In: Journal of Physics: Conference Series, Institute of Physics (IOP), 2016Conference paper (Refereed)
    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.

  • 26.
    Berglund, Martin
    et al.
    Uppsala University, Disciplinary Domain of Science and Technology, Technology, Department of Engineering Sciences, Microsystems Technology.
    Palmer, Kristoffer
    Uppsala University, Disciplinary Domain of Science and Technology, Technology, Department of Engineering Sciences, Microsystems Technology.
    Lotfi, Sara
    Uppsala University, Disciplinary Domain of Science and Technology, Technology, Department of Engineering Sciences, Solid State Electronics.
    Kratz, Henrik
    Uppsala University, Disciplinary Domain of Science and Technology, Technology, Department of Engineering Sciences, Microsystems Technology.
    Thornell, Greger
    Uppsala University, Disciplinary Domain of Science and Technology, Technology, Department of Engineering Sciences, Microsystems Technology.
    Dynamic characterization and modelling of a dual-axis beam steering device for performance understanding, optimization, and control design2013In: Journal of Micromechanics and Microengineering, ISSN 0960-1317, E-ISSN 1361-6439, Vol. 23, no 4, p. 045020-Article in journal (Refereed)
    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.

  • 27.
    Berglund, Martin
    et al.
    Uppsala University, Disciplinary Domain of Science and Technology, Technology, Department of Engineering Sciences, Microsystems Technology.
    Persson, Anders
    Uppsala University, Disciplinary Domain of Science and Technology, Physics, Department of Physics and Astronomy.
    Kratz, Henrik
    Uppsala University, Disciplinary Domain of Science and Technology, Technology, Department of Engineering Sciences, Microsystems Technology.
    Thornell, Greger
    Uppsala University, Disciplinary Domain of Science and Technology, Technology, Department of Engineering Sciences, Microsystems Technology.
    Microfluidics integrable plasma source powered by a silicon through-substrate split-ring resonator2013In: Solid-State Sensors, Actuators and Microsystems (TRANSDUCERS EUROSENSORS XXVII), 2013, p. 2608-2611Conference paper (Other academic)
    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.

  • 28.
    Berglund, Martin
    et al.
    Uppsala University, Disciplinary Domain of Science and Technology, Technology, Department of Engineering Sciences, Microsystems Technology.
    Persson, Anders
    Uppsala University, Disciplinary Domain of Science and Technology, Technology, Department of Engineering Sciences, Microsystems Technology.
    Thornell, Greger
    Uppsala University, Disciplinary Domain of Science and Technology, Technology, Department of Engineering Sciences, Microsystems Technology.
    A High-Performance Microplasma Source for Highly Sensitive and Robust Gas Analysis2014In: Proc. of Micronano System Workshop 2014, Uppsala, Sweden, May 15-16, 2014, 2014Conference paper (Other academic)
  • 29.
    Berglund, Martin
    et al.
    Uppsala University, Disciplinary Domain of Science and Technology, Technology, Department of Engineering Sciences, Microsystems Technology.
    Persson, Anders
    Uppsala University, Disciplinary Domain of Science and Technology, Technology, Department of Engineering Sciences, Microsystems Technology.
    Thornell, Greger
    Uppsala University, Disciplinary Domain of Science and Technology, Technology, Department of Engineering Sciences, Microsystems Technology.
    Evaluation of dielectric properties of HTCC alumina for realization of plasma sources2015In: Journal of Electronic Materials, ISSN 0361-5235, E-ISSN 1543-186X, Vol. 44, no 10, p. 3654-3660Article in journal (Refereed)
    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.

  • 30.
    Berglund, Martin
    et al.
    Uppsala University, Disciplinary Domain of Science and Technology, Technology, Department of Engineering Sciences, Microsystems Technology.
    Sturesson, Peter
    Uppsala University, Disciplinary Domain of Science and Technology, Technology, Department of Engineering Sciences, Microsystems Technology. Swedish Defence University.
    Thornell, Greger
    Uppsala University, Disciplinary Domain of Science and Technology, Technology, Department of Engineering Sciences, Microsystems Technology.
    Persson, Anders
    Uppsala University, Disciplinary Domain of Science and Technology, Technology, Department of Engineering Sciences, Microsystems Technology.
    Manufacturing Miniature Langmuir probes by Fusing Platinum Bond Wires2015In: Journal of Micromechanics and Microengineering, ISSN 0960-1317, E-ISSN 1361-6439, Vol. 25, no 10, article id 105012Article in journal (Refereed)
    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.

  • 31.
    Berglund, Martin
    et al.
    Uppsala University, Disciplinary Domain of Science and Technology, Technology, Department of Engineering Sciences, Microsystems Technology.
    Thornell, Greger
    Uppsala University, Disciplinary Domain of Science and Technology, Technology, Department of Engineering Sciences, Microsystems Technology.
    Persson, Anders
    Uppsala University, Disciplinary Domain of Science and Technology, Physics, Department of Physics and Astronomy. Uppsala University, Disciplinary Domain of Science and Technology, Technology, Department of Engineering Sciences, Microsystems Technology.
    Microplasma source for optogalvanic spectroscopy of nanogram samples2013In: Journal of Applied Physics, ISSN 0021-8979, E-ISSN 1089-7550, Vol. 114, no 3, p. 033302-Article in journal (Refereed)
    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.

  • 32.
    Björnander Rahimi, Klara
    Uppsala University, Disciplinary Domain of Science and Technology, Technology, Department of Engineering Sciences, Microsystems Technology.
    Enrichment of microparticles in droplets using acoustophoresis2018Independent thesis Advanced level (professional degree), 20 credits / 30 HE creditsStudent thesis
    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.

  • 33.
    Blomqvist, Mikael
    Uppsala University, Disciplinary Domain of Science and Technology, Technology, Department of Engineering Sciences, Microsystems Technology, Ångström Space Technology Centre (ÅSTC).
    Construction and evaluation of a magnetoresistive ground penetrating radar system2011Independent thesis Advanced level (professional degree), 20 credits / 30 HE creditsStudent thesis
    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.

  • 34.
    Boden, Roger
    et al.
    Uppsala University, Disciplinary Domain of Science and Technology, Technology, Department of Engineering Sciences, Microsystems Technology. Materialvetenskap.
    Simu, U.
    Margell, J.
    Lehto, Marcus
    Uppsala University, Disciplinary Domain of Science and Technology, Technology, Department of Engineering Sciences, Materials Science. Materialvetenskap.
    Hjort, Klas
    Uppsala University, Disciplinary Domain of Science and Technology, Technology, Department of Engineering Sciences, Microsystems Technology. Materialvetenskap.
    Thornell, Greger
    Uppsala University, Disciplinary Domain of Science and Technology, Technology, Department of Engineering Sciences, Microsystems Technology. Materialvetenskap.
    Schweitz, Jan-Åke
    Uppsala University, Disciplinary Domain of Science and Technology, Technology, Department of Engineering Sciences, Microsystems Technology. Materialvetenskap.
    Metallic high-pressure microfluidicpump with active valves2007Conference paper (Refereed)
  • 35.
    Bodén, Roger
    et al.
    Uppsala University, Disciplinary Domain of Science and Technology, Technology, Department of Engineering Sciences, Microsystems Technology.
    Hjort, Klas
    Uppsala University, Disciplinary Domain of Science and Technology, Technology, Department of Engineering Sciences, Microsystems Technology.
    Schweitz, Jan-Åke
    Uppsala University, Disciplinary Domain of Science and Technology, Technology, Department of Engineering Sciences, Microsystems Technology.
    Simu, Urban
    Uppsala University, Disciplinary Domain of Science and Technology, Technology, Department of Engineering Sciences, Microsystems Technology.
    A metallic micropump for high-pressure microfluidics2008In: Journal of Micromechanics and Microengineering, ISSN 0960-1317, E-ISSN 1361-6439, Vol. 18, no 11, p. 115009-Article in journal (Refereed)
    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.

  • 36.
    Bodén, Roger
    et al.
    Uppsala University, Disciplinary Domain of Science and Technology, Technology, Department of Engineering Sciences, Microsystems Technology.
    Hjort, Klas
    Uppsala University, Disciplinary Domain of Science and Technology, Technology, Department of Engineering Sciences, Microsystems Technology.
    Simu, Urban
    Schweitz, Jan-Åke
    Uppsala University, Disciplinary Domain of Science and Technology, Technology, Department of Engineering Sciences, Microsystems Technology.
    Metallic high-pressure microfluidic pump2008In: MSW08, 2008, p. 29-Conference paper (Refereed)
  • 37.
    Bodén, Roger
    et al.
    Uppsala University, Disciplinary Domain of Science and Technology, Technology, Department of Engineering Sciences, Materials Science.
    Lehto, Marcus
    Uppsala University, Disciplinary Domain of Science and Technology, Technology, Department of Engineering Sciences, Materials Science.
    Simu, Urban
    Thornell, Greger
    Uppsala University, Disciplinary Domain of Science and Technology, Technology, Department of Engineering Sciences, Microsystems Technology.
    Hjort, Klas
    Uppsala University, Disciplinary Domain of Science and Technology, Technology, Department of Engineering Sciences, Microsystems Technology.
    Schweitz, Jan-Åke
    Uppsala University, Disciplinary Domain of Science and Technology, Technology, Department of Engineering Sciences, Materials Science.
    A polymeric paraffin actuated high-pressure micropump2006In: Sensors and Actuators A, ISSN 0924-4247, Vol. 127, no 1, p. 88-93Article in journal (Refereed)
  • 38.
    Bodén, Roger
    et al.
    Uppsala University, Disciplinary Domain of Science and Technology, Technology, Department of Engineering Sciences, Materials Science.
    Lehto, Marcus
    Uppsala University, Disciplinary Domain of Science and Technology, Technology, Department of Engineering Sciences, Materials Science.
    Simu, Urban
    Uppsala University, Disciplinary Domain of Science and Technology, Technology, Department of Engineering Sciences, Materials Science.
    Thornell, Greger
    Uppsala University, Disciplinary Domain of Science and Technology, Technology, Department of Engineering Sciences, Materials Science.
    Hjort, Klas
    Uppsala University, Disciplinary Domain of Science and Technology, Technology, Department of Engineering Sciences, Microsystems Technology.
    Schweitz, Jan-Åke
    Uppsala University, Disciplinary Domain of Science and Technology, Technology, Department of Engineering Sciences, Materials Science.
    A polymeric paraffin actuated high-pressure micropump2006In: Sensors and Actuators A: Physical, ISSN 0924-4247, Vol. 127, no 1, p. 88-93Article in journal (Refereed)
  • 39.
    Bodén, Roger
    et al.
    Uppsala University, Disciplinary Domain of Science and Technology, Technology, Department of Engineering Sciences, Materials Science.
    Lehto, Marcus
    Uppsala University, Disciplinary Domain of Science and Technology, Technology, Department of Engineering Sciences, Materials Science.
    Simu, Urban
    Uppsala University, Disciplinary Domain of Science and Technology, Technology, Department of Engineering Sciences, Materials Science.
    Thornell, Greger
    Uppsala University, Disciplinary Domain of Science and Technology, Technology, Department of Engineering Sciences, Materials Science.
    Hjort, Klas
    Uppsala University, Disciplinary Domain of Science and Technology, Technology, Department of Engineering Sciences, Microsystems Technology.
    Schweitz, Jan-Åke
    Uppsala University, Disciplinary Domain of Science and Technology, Technology, Department of Engineering Sciences, Materials Science.
    A polymeric paraffin actuated high-pressure micropump2006In: Sensors and Actuators A-Physical, ISSN 0924-4247, E-ISSN 1873-3069, Vol. 127, no 1, p. 88-93Article in journal (Refereed)
  • 40.
    Bodén, Roger
    et al.
    Uppsala University, Disciplinary Domain of Science and Technology, Technology, Department of Engineering Sciences, Microsystems Technology.
    Ogden, Sam
    Uppsala University, Disciplinary Domain of Science and Technology, Technology, Department of Engineering Sciences, Microsystems Technology.
    Hjort, Klas
    Uppsala University, Disciplinary Domain of Science and Technology, Technology, Department of Engineering Sciences, Microsystems Technology.
    Microdispenser with continuous flow and selectable target volume for microfluidic high-pressure applications2014In: Journal of microelectromechanical systems, ISSN 1057-7157, E-ISSN 1941-0158, Vol. 23, no 2, p. 452-458Article in journal (Refereed)
    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

  • 41.
    Brinnen, Mikael
    et al.
    Uppsala University, Disciplinary Domain of Science and Technology, Technology, Department of Engineering Sciences, Microsystems Technology.
    Laggar, Gustaf
    Uppsala University, Disciplinary Domain of Science and Technology, Technology, Department of Engineering Sciences, Microsystems Technology.
    New Cutting Tool Concept For Cylinder Boring2016Independent thesis Basic level (professional degree), 10 credits / 15 HE creditsStudent thesis
    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. 

  • 42.
    Carter, Sarah-Sophia
    et al.
    Uppsala University, Disciplinary Domain of Science and Technology, Technology, Department of Engineering Sciences, Microsystems Technology.
    Atif, Abdul
    Uppsala University, Disciplinary Domain of Science and Technology, Technology, Department of Engineering Sciences, Microsystems Technology.
    Lanekoff, Ingela
    Uppsala University, Disciplinary Domain of Science and Technology, Chemistry, Department of Chemistry - BMC, Analytical Chemistry.
    Tenje, Maria
    Uppsala University, Disciplinary Domain of Science and Technology, Technology, Department of Engineering Sciences, Microsystems Technology.
    Mestres, Gemma
    Uppsala University, Disciplinary Domain of Science and Technology, Technology, Department of Engineering Sciences, Microsystems Technology.
    Tailoring the biocompatibility of the elastomer PDMS for on-chip applications2018Conference paper (Refereed)
  • 43.
    Carter, Sarah-Sophia
    et al.
    Uppsala University, Disciplinary Domain of Science and Technology, Technology, Department of Engineering Sciences, Microsystems Technology.
    Atif, Abdul Raouf M.
    Uppsala University, Disciplinary Domain of Science and Technology, Technology, Department of Engineering Sciences, Microsystems Technology.
    Lanekoff, Ingela
    Uppsala University, Disciplinary Domain of Science and Technology, Chemistry, Department of Chemistry - BMC, Analytical Chemistry.
    Tenje, Maria
    Uppsala University, Disciplinary Domain of Science and Technology, Technology, Department of Engineering Sciences, Microsystems Technology.
    Mestres, Gemma
    Uppsala University, Disciplinary Domain of Science and Technology, Technology, Department of Engineering Sciences, Microsystems Technology.
    Improving the biocompatibility of PDMS by improving its curing time and temperature2018Conference paper (Other academic)
  • 44.
    Carter, Sarah-Sophia
    et al.
    Uppsala University, Disciplinary Domain of Science and Technology, Technology, Department of Engineering Sciences, Microsystems Technology.
    Cruz, Javier
    Uppsala University, Disciplinary Domain of Science and Technology, Technology, Department of Engineering Sciences, Microsystems Technology.
    Tenje, Maria
    Uppsala University, Disciplinary Domain of Science and Technology, Technology, Department of Engineering Sciences, Microsystems Technology. Uppsala University, Science for Life Laboratory, SciLifeLab.
    Mestres, Gemma
    Uppsala University, Disciplinary Domain of Science and Technology, Technology, Department of Engineering Sciences, Microsystems Technology. Uppsala University, Science for Life Laboratory, SciLifeLab.
    Towards the development of a microfluidic tool to assess the biological properties of biomaterials for bone regeneration2018Conference paper (Refereed)
  • 45.
    Chabera, Pavel
    et al.
    Lund Univ, Dept Chem, Div Phys Chem, Box 124, SE-22100 Lund, Sweden..
    Liu, Yizhu
    Lund Univ, Dept Chem, CAS, Box 124, SE-22100 Lund, Sweden..
    Prakash, Om
    Lund Univ, Dept Chem, CAS, Box 124, SE-22100 Lund, Sweden..
    Thyrhaug, Erling
    Lund Univ, Dept Chem, Div Phys Chem, Box 124, SE-22100 Lund, Sweden..
    El Nahhas, Amal
    Lund Univ, Dept Chem, Div Phys Chem, Box 124, SE-22100 Lund, Sweden..
    Honarfar, Alireza
    Lund Univ, Dept Chem, Div Phys Chem, Box 124, SE-22100 Lund, Sweden..
    Essen, Sofia
    Lund Univ, Dept Chem, CAS, Box 124, SE-22100 Lund, Sweden..
    Fredin, Lisa A.
    Lund Univ, Dept Chem, Div Theoret Chem, Box 124, SE-22100 Lund, Sweden..
    Harlang, Tobias C. B.
    Lund Univ, Dept Chem, Div Phys Chem, Box 124, SE-22100 Lund, Sweden.;Tech Univ Denmark, Dept Phys, DK-2800 Lyngby, Denmark..
    Kjaer, Kasper S.
    Lund Univ, Dept Chem, Div Phys Chem, Box 124, SE-22100 Lund, Sweden.;Tech Univ Denmark, Dept Phys, DK-2800 Lyngby, Denmark..
    Handrup, Karsten
    Lund Univ, Dept Phys, Div Synchrotron Radiat Res, Box 118, SE-22100 Lund, Sweden..
    Ericson, Fredric
    Uppsala University, Disciplinary Domain of Science and Technology, Technology, Department of Engineering Sciences, Microsystems Technology.
    Tatsuno, Hideyuki
    Lund Univ, Dept Chem, Div Phys Chem, Box 124, SE-22100 Lund, Sweden..
    Morgan, Kelsey
    NIST, Boulder, CO 80305 USA..
    Schnadt, Joachim
    Lund Univ, Dept Phys, Div Synchrotron Radiat Res, Box 118, SE-22100 Lund, Sweden..
    Häggström, Lennart
    Uppsala University, Disciplinary Domain of Science and Technology, Physics, Department of Physics and Astronomy, Materials Physics.
    Ericsson, Tore
    Uppsala University, Disciplinary Domain of Science and Technology, Physics, Department of Physics and Astronomy, Materials Physics.
    Sobkowiak, Adam
    Uppsala University, Disciplinary Domain of Science and Technology, Chemistry, Department of Chemistry - Ångström, Structural Chemistry.
    Lidin, Sven
    Lund Univ, Dept Chem, CAS, Box 124, SE-22100 Lund, Sweden..
    Huang, Ping
    Uppsala University, Disciplinary Domain of Science and Technology, Chemistry, Department of Chemistry - Ångström, Molecular Biomimetics.
    Styring, Stenbjörn
    Uppsala University, Disciplinary Domain of Science and Technology, Chemistry, Department of Chemistry - Ångström, Molecular Biomimetics.
    Uhlig, Jens
    Lund Univ, Dept Chem, Div Phys Chem, Box 124, SE-22100 Lund, Sweden..
    Bendix, Jesper
    Univ Copenhagen, Dept Chem, Univ Pk 5, DK-2100 Copenhagen, Denmark..
    Lomoth, Reiner
    Uppsala University, Disciplinary Domain of Science and Technology, Chemistry, Department of Chemistry - Ångström, Physical Chemistry.
    Sundström, Villy
    Lund Univ, Dept Chem, Div Phys Chem, Box 124, SE-22100 Lund, Sweden..
    Persson, Petter
    Lund Univ, Dept Chem, Div Theoret Chem, Box 124, SE-22100 Lund, Sweden..
    Warnmark, Kenneth
    Lund Univ, Dept Chem, CAS, Box 124, SE-22100 Lund, Sweden..
    A low-spin Fe(III) complex with 100-ps ligand-to-metal charge transfer photoluminescence2017In: Nature, ISSN 0028-0836, E-ISSN 1476-4687, Vol. 543, no 7647, p. 695-+Article in journal (Refereed)
    Abstract [en]

    Transition-metal complexes are used as photosensitizers(1), in light-emitting diodes, for biosensing and in photocatalysis(2). A key feature in these applications is excitation from the ground state to a charge-transfer state(3,4); the long charge-transfer-state lifetimes typical for complexes of ruthenium(5) and other precious metals are often essential to ensure high performance. There is much interest in replacing these scarce elements with Earth-abundant metals, with iron(6) and copper(7) being particularly attractive owing to their low cost and non-toxicity. But despite the exploration of innovative molecular designs(6,8-10), it remains a formidable scientific challenge(11) to access Earth-abundant transition-metal complexes with long-lived charge-transfer excited states. No known iron complexes are considered(12) photoluminescent at room temperature, and their rapid excited-state deactivation precludes their use as photosensitizers(13-15). Here we present the iron complex [Fe(btz)(3)](3+) (where btz is 3,3'-dimethyl-1,1'-bis(p-tolyl)-4,4'-bis(1,2,3-triazol-5-ylidene)), and show that the superior sigma-donor and pi-acceptor electron properties of the ligand stabilize the excited state sufficiently to realize a long charge-transfer lifetime of 100 picoseconds (ps) and room-temperature photoluminescence. This species is a low-spin Fe(III) d(5) complex, and emission occurs from a long-lived doublet ligand-to-metal charge-transfer ((LMCT)-L-2) state that is rarely seen for transition-metal complexes(4,16,17). The absence of intersystem crossing, which often gives rise to large excited-state energy losses in transition-metal complexes, enables the observation of spin-allowed emission directly to the ground state and could be exploited as an increased driving force in photochemical reactions on surfaces. These findings suggest that appropriate design strategies can deliver new iron-based materials for use as light emitters and photosensitizers.

  • 46.
    Chang, Bo
    et al.
    Uppsala University, Disciplinary Domain of Science and Technology, Technology, Department of Engineering Sciences, Microsystems Technology.
    Hjort, Klas
    Uppsala University, Disciplinary Domain of Science and Technology, Technology, Department of Engineering Sciences, Microsystems Technology.
    Shah, Ali
    Aalto University, Finland.
    Zhou, Quan
    Aalto University, Finland.
    HYDROPHILIC-SUPERHYDROPHOBIC PATTERNED SURFACE FOR PARALLEL MICROASSEMBLY2014In: Technical Digest of the 25th Micromechanics and Microsystems Europe Conference (MME 2014), Istanbul, Turkey, 2014, 2014Conference paper (Refereed)
    Abstract [en]

    In  this  paper,  a  hydrophilic-superhydrophobic  patterned  surface  is  investigated for parallel microassembly of 200 µm × 200 µm chips with receptor sites of the same dimensions, allowing for correction of significant error as compared to the state-of-the-art.  The  hydrophilic-superhydrophobic pattered surface consists of 200 µm × 200 µm silicondioxide  receptor  sites  with  black  silicon  substrate coated  with  fluorocarbon  polymer.  The  measured contact  angle  of  water  on  the  silicon  dioxide  padsand the background are 50° and 170°, respectively.The  water  mist-induced  hybrid  microassembly technique  is  used  to  carry  out  the  experimental studies  on  hydrophilic-superhydrophobic  pattered surface  for  parallel  microassembly.  The  experimental results show that the parallel microassembly of  chips  can  not  only  be  achieved  on  hydrophilic-superhydrophobic  patterned  surface,  but  also demonstrate  significant  error  correction  capability. With extreme large initial placement error,  where achip  is  placed  next  to  a receptor  site  and  has  zero overlapping  with  the  receptor  site,  the  chip  is  still able to align with the receptor site. The results also indicate  that  the  reliability  of  the  microassembly process  can  be  greatly  enhanced  using  hydrophilic patterns with super-hydrophobic background.

  • 47.
    Chang, Bo
    et al.
    Uppsala University, Disciplinary Domain of Science and Technology, Technology, Department of Engineering Sciences, Microsystems Technology.
    Shah, Ali
    Aalto University.
    Zhou, Quan
    Aalto University.
    Ras, Robin
    Aalto University.
    Hjort, Klas
    Uppsala University, Disciplinary Domain of Science and Technology, Technology, Department of Engineering Sciences, Microsystems Technology.
    Self-transport and self-alignment of microchips using microscopic rain2015In: Scientific Reports, ISSN 2045-2322, E-ISSN 2045-2322, Vol. 5, article id 14966Article in journal (Refereed)
    Abstract [en]

    Alignment of microchips with receptors is an important process step in the construction of integrated micro- and nanosystems for emerging technologies, and facilitating alignment by spontaneous self-assembly processes is highly desired. Previously, capillary self-alignment of microchips driven by surface tension effects on patterned surfaces has been reported, where it was essential for microchips to have sufficient overlap with receptor sites. Here we demonstrate for the first time capillary self-transport and self-alignment of microchips, where microchips are initially placed outside the corresponding receptor sites and can be self-transported by capillary force to the receptor sites followed by self-alignment. The surface consists of hydrophilic silicon receptor sites surrounded by superhydrophobic black silicon. Rain-induced microscopic droplets are used to form the meniscus for the self-transport and self-alignment. The boundary conditions for the self-transport have been explored by modeling and confirmed experimentally. The maximum permitted gap between a microchip and a receptor site is determined by the volume of the liquid and by the wetting contrast between receptor site and substrate. Microscopic rain applied on hydrophilic-superhydrophobic patterned surfaces greatly improves the capability, reliability and error-tolerance of the process, avoiding the need for accurate initial placement of microchips, and thereby greatly simplifying the alignment process.

  • 48.
    Chang, Bo
    et al.
    Uppsala University, Disciplinary Domain of Science and Technology, Technology, Department of Engineering Sciences, Microsystems Technology.
    Zhou, Quan
    Aalto University, Finland.
    Ras, Robin
    Aalto University, Finland.
    Shah, Ali
    Aalto University, Finland.
    Wu, Zhigang
    Uppsala University, Disciplinary Domain of Science and Technology, Technology, Department of Engineering Sciences, Microsystems Technology.
    Hjort, Klas
    Uppsala University, Disciplinary Domain of Science and Technology, Technology, Department of Engineering Sciences, Microsystems Technology.
    Sliding droplets on hydrophilic/superhydrophobic patterned surfaces for liquid deposition2016In: Applied Physics Letters, ISSN 0003-6951, E-ISSN 1077-3118, Vol. 108, no 15, article id 154102Article in journal (Refereed)
    Abstract [en]

    A facile gravity-induced sliding droplets method is reported for deposition of nanoliter sized droplets on hydrophilic/superhydrophobic patterned surface. The deposition process is parallel where multiple different liquids can be deposited simultaneously. The process is also high-throughput, having a great potential to be scaled up by increasing the size of the substrate.

  • 49.
    Chang, Bo
    et al.
    Uppsala University, Disciplinary Domain of Science and Technology, Technology, Department of Engineering Sciences, Microsystems Technology. Aalto Univ, Sch Sci, Dept Appl Phys, FI-00076 Aalto, Finland.
    Zhou, Quan
    Aalto Univ, Dept Elect Engn & Automat, FI-00076 Aalto, Finland.
    Wu, Zhigang
    Uppsala University, Disciplinary Domain of Science and Technology, Technology, Department of Engineering Sciences, Microsystems Technology. Huazhong Univ Sci & Technol, State Key Lab Digital Mfg Equipment & Technol, Wuhan 430074, Peoples R China.
    Ras, Robin
    Aalto Univ, Sch Sci, Dept Appl Phys, FI-00076 Aalto, Finland.
    Hjort, Klas
    Uppsala University, Disciplinary Domain of Science and Technology, Technology, Department of Engineering Sciences, Microsystems Technology.
    Capillary Self-Alignment of Microchips on Soft Substrates2016In: Micromachines, ISSN 2072-666X, E-ISSN 2072-666X, Vol. 7, no 3, article id 41Article in journal (Refereed)
    Abstract [en]

    Soft micro devices and stretchable electronics have attracted great interest for their potential applications in sensory skins and wearable bio-integrated devices. One of the most important steps in building printed circuits is the alignment of assembled micro objects. Previously, the capillary self-alignment of microchips driven by surface tension effects has been shown to be able to achieve high-throughput and high-precision in the integration of micro parts on rigid hydrophilic/superhydrophobic patterned surfaces. In this paper, the self-alignment of microchips on a patterned soft and stretchable substrate, which consists of hydrophilic pads surrounded by a superhydrophobic polydimethylsiloxane (PDMS) background, is demonstrated for the first time. A simple process has been developed for making superhydrophobic soft surface by replicating nanostructures of black silicon onto a PDMS surface. Different kinds of PDMS have been investigated, and the parameters for fabricating superhydrophobic PDMS have been optimized. A self-alignment strategy has been proposed that can result in reliable self-alignment on a soft PDMS substrate. Our results show that capillary self-alignment has great potential for building soft printed circuits.

  • 50.
    Chang, Bo
    et al.
    Uppsala University, Disciplinary Domain of Science and Technology, Technology, Department of Engineering Sciences, Microsystems Technology.
    Zhou, Quan
    Wu, Zhigang
    Uppsala University, Disciplinary Domain of Science and Technology, Technology, Department of Engineering Sciences, Microsystems Technology.
    Ras, Robin
    Hjort, Klas
    Uppsala University, Disciplinary Domain of Science and Technology, Technology, Department of Engineering Sciences, Microsystems Technology.
    Superhydrophobic PDMS for capillary self-alignment2016In: 11th Micronano System Workshop (MSW 2016), 2016, Vol. 11, article id P19Conference paper (Refereed)
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