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  • 1.
    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.

  • 2.
    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.

  • 3.
    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.

  • 4.
    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)
  • 5.
    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.

  • 6.
    Berglund, Martin
    et al.
    Uppsala University, Disciplinary Domain of Science and Technology, Technology, Department of Engineering Sciences, Applied Materials Sciences.
    Persson, Anders
    Uppsala University, Disciplinary Domain of Science and Technology, Physics, Department of Physics and Astronomy, Applied Nuclear Physics.
    Thornell, Greger
    Uppsala University, Disciplinary Domain of Science and Technology, Technology, Department of Engineering Sciences, Applied Materials Sciences.
    Operation characteristics and optical emission distribution of a miniaturized silicon through-substrate split-ring resonator microplasma source2014In: Journal of microelectromechanical systems, ISSN 1057-7157, E-ISSN 1941-0158, Vol. 23, no 6, p. 1340-1345Article in journal (Refereed)
    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.

  • 7.
    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.

  • 8.
    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.

  • 9.
    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)
  • 10.
    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)
  • 11.
    Bodén, Roger
    et al.
    Uppsala University, Teknisk-naturvetenskapliga vetenskapsområdet, Technology, Department of Engineering Sciences. Uppsala University, Teknisk-naturvetenskapliga vetenskapsområdet, Physics, Department of Physics and Materials Science, Materials Science.
    Lehto, Marcus
    Uppsala University, Teknisk-naturvetenskapliga vetenskapsområdet, Technology, Department of Engineering Sciences. Uppsala University, Teknisk-naturvetenskapliga vetenskapsområdet, Physics, Department of Physics and Materials Science, Materials Science.
    Simu, Urban
    Uppsala University, Teknisk-naturvetenskapliga vetenskapsområdet, Technology, Department of Engineering Sciences. Uppsala University, Teknisk-naturvetenskapliga vetenskapsområdet, Physics, Department of Physics and Materials Science, Materials Science.
    Thornell, Greger
    Uppsala University, Teknisk-naturvetenskapliga vetenskapsområdet, Technology, Department of Engineering Sciences. Uppsala University, Teknisk-naturvetenskapliga vetenskapsområdet, Physics, Department of Physics and Materials Science, Materials Science.
    Hjort, Klas
    Uppsala University, Teknisk-naturvetenskapliga vetenskapsområdet, Technology, Department of Engineering Sciences. Uppsala University, Teknisk-naturvetenskapliga vetenskapsområdet, Physics, Department of Physics and Materials Science, Materials Science.
    Schweitz, Jan-Åke
    Uppsala University, Teknisk-naturvetenskapliga vetenskapsområdet, Technology, Department of Engineering Sciences. Uppsala University, Teknisk-naturvetenskapliga vetenskapsområdet, Physics, Department of Physics and Materials Science, Materials Science.
    A Polymeric Paraffin Micropump with Active Valves for High-Pressure Microfluidics2005In: The 13th International Conference on Solid-State Sensors, Actuators and Microsystems, Seoul, Korea, 2005Conference paper (Refereed)
  • 12.
    Bodén, Roger
    et al.
    Uppsala University, Teknisk-naturvetenskapliga vetenskapsområdet, Technology, Department of Engineering Sciences. Uppsala University, Teknisk-naturvetenskapliga vetenskapsområdet, Physics, Department of Physics and Materials Science, Materials Science.
    Lehto, Marcus
    Uppsala University, Teknisk-naturvetenskapliga vetenskapsområdet, Technology, Department of Engineering Sciences. Uppsala University, Teknisk-naturvetenskapliga vetenskapsområdet, Physics, Department of Physics and Materials Science, Materials Science.
    Thornell, Greger
    Uppsala University, Teknisk-naturvetenskapliga vetenskapsområdet, Technology, Department of Engineering Sciences. Uppsala University, Teknisk-naturvetenskapliga vetenskapsområdet, Physics, Department of Physics and Materials Science, Materials Science.
    Hjort, Klas
    Uppsala University, Teknisk-naturvetenskapliga vetenskapsområdet, Technology, Department of Engineering Sciences. Uppsala University, Teknisk-naturvetenskapliga vetenskapsområdet, Physics, Department of Physics and Materials Science, Materials Science.
    Schweitz, Jan-Åke
    Uppsala University, Teknisk-naturvetenskapliga vetenskapsområdet, Technology, Department of Engineering Sciences. Uppsala University, Teknisk-naturvetenskapliga vetenskapsområdet, Physics, Department of Physics and Materials Science, Materials Science.
    A polymeric paraffin actuated high-pressure micropump2005In: SenArticle in journal (Refereed)
  • 13.
    Böhnke, Tobias
    et al.
    Uppsala University, Disciplinary Domain of Science and Technology, Technology, Department of Engineering Sciences, Division for Electricity and Lightning Research.
    Kratz, Henrik
    Uppsala University, Disciplinary Domain of Science and Technology, Technology, Department of Engineering Sciences, Micro Structural Technology.
    Hultåker, Annette
    Uppsala University, Disciplinary Domain of Science and Technology, Technology, Department of Engineering Sciences, Solid State Physics.
    Köhler, Johan
    Uppsala University, Disciplinary Domain of Science and Technology, Technology, Department of Engineering Sciences, Division for Electricity and Lightning Research.
    Edoff, Marika
    Uppsala University, Disciplinary Domain of Science and Technology, Technology, Department of Engineering Sciences, Solid State Electronics.
    Roos, Arne
    Uppsala University, Disciplinary Domain of Science and Technology, Technology, Department of Engineering Sciences, Solid State Physics.
    Ribbing, Carl-Gustaf
    Uppsala University, Disciplinary Domain of Science and Technology, Technology, Department of Engineering Sciences, Solid State Physics.
    Thornell, Greger
    Uppsala University, Disciplinary Domain of Science and Technology, Technology, Department of Engineering Sciences, Micro Structural Technology.
    Surfaces with high solar reflectance and high thermal emittance on structured silicon for spacecraft thermal control2008In: Optical materials (Amsterdam), ISSN 0925-3467, E-ISSN 1873-1252, Vol. 30, no 9, p. 1410-1421Article in journal (Refereed)
    Abstract [en]

    Presented here is an examination of unstructured and structured (by anisotropic etching), monocrystalline silicon wafers coated with sputter deposited aluminum and chemical vapor deposited silicon dioxide for high solar reflectance and high thermal emittance, respectively. The topography of the samples was characterized with optical and scanning electron microscopy. Optical properties were examined with reflectance and transmittance spectroscopy, partly by usage of an integrating sphere. The measurement results were used to estimate the equilibrium temperature of the surfaces in space. The suitability of the surfaces with high solar reflectance and high thermal emittance to aid in the thermal control of miniaturized, highly integrated components for space applications is discussed. A silicon dioxide layer on a metal layer results in a slightly lower reflectance when compared to surfaces with only a metal layer, but might be beneficial for miniaturized space components and modules that have to dissipate internally generated heat into open space. Additionally, it is an advantage to microstructure the emitting surface for enhanced radiation of excess heat.

  • 14. Gurgurewicz, Joanna
    et al.
    Mège, Daniel
    Grygorczuk, Jerzy
    Wiśniewski, Łukasz
    Berglund, Martin
    Uppsala University, Disciplinary Domain of Science and Technology, Technology, Department of Engineering Sciences, Microsystems Technology.
    Carrère, Véronique
    Gritsevich, Maria
    Kalarus, Maciej
    Peltoniemi, Jouni
    Persson, Anders
    Uppsala University, Disciplinary Domain of Science and Technology, Technology, Department of Engineering Sciences, Microsystems Technology.
    Rataj, Mirosław
    Thornell, Greger
    Uppsala University, Disciplinary Domain of Science and Technology, Technology, Department of Engineering Sciences, Microsystems Technology.
    Wawer, Piotr
    Zubko, Nataliya
    Studying the composition of Phobos' surface using HOPTER (Highland Terrain Hopper)2016Conference paper (Refereed)
  • 15.
    Gustafsson, Theres
    et al.
    Uppsala University, Disciplinary Domain of Science and Technology, Technology, Department of Engineering Sciences, Materials Science.
    Linvall, Anders
    Uppsala University, Disciplinary Domain of Science and Technology, Technology, Department of Engineering Sciences, Materials Science.
    Lindegren, Robert
    Thornell, Greger
    Uppsala University, Disciplinary Domain of Science and Technology, Technology, Department of Engineering Sciences, Materials Science.
    A cost and lead time astimation tool for MEMS manufacturing2006Conference paper (Refereed)
  • 16. Gustafsson, Theres
    et al.
    Thornell, Greger
    Uppsala University, Disciplinary Domain of Science and Technology, Technology, Department of Engineering Sciences, Materials Science.
    Manufacturing Cost and Lead Time Calculation Applied to Highly Miniaturized Systems in Space2006Conference paper (Refereed)
  • 17. Janhunen, P.
    et al.
    Toivanen, P. K.
    Polkko, J.
    Merikallio, S.
    Salminen, P.
    Haeggstrom, E.
    Seppänen, H.
    Kurppa, R.
    Ukkonen, J.
    Kiprich, S.
    Thornell, Greger
    Uppsala University, Disciplinary Domain of Science and Technology, Technology, Department of Engineering Sciences, Microsystems Technology.
    Kratz, Henrik
    Uppsala University, Disciplinary Domain of Science and Technology, Technology, Department of Engineering Sciences, Microsystems Technology.
    Richter, L.
    Krömer, O.
    Rosta, R.
    Noorma, M.
    Envall, J.
    Lätt, S.
    Mengali, G.
    Quarta, A. A.
    Koivisto, H.
    Tarvainen, O.
    Kalvas, T.
    Kauppinen, J.
    Nuottajärvi, A.
    Obraztsov, A.
    Invited Article: Electric solar wind sail: Toward test missions2010In: Review of Scientific Instruments, ISSN 0034-6748, E-ISSN 1089-7623, Vol. 81, no 11, p. 111301-Article in journal (Refereed)
    Abstract [en]

    The electric solar wind sail (E-sail) is a space propulsion concept that uses the natural solar wind dynamic pressure for producing spacecraft thrust. In its baseline form, the E-sail consists of a number of long, thin, conducting, and centrifugally stretched tethers, which are kept in a high positive potential by an onboard electron gun. The concept gains its efficiency from the fact that the effective sail area, i.e., the potential structure of the tethers, can be millions of times larger than the physical area of the thin tethers wires, which offsets the fact that the dynamic pressure of the solar wind is very weak. Indeed, according to the most recent published estimates, an E-sail of 1 N thrust and 100 kg mass could be built in the rather near future, providing a revolutionary level of propulsive performance (specific acceleration) for travel in the solar system. Here we give a review of the ongoing technical development work of the E-sail, covering tether construction, overall mechanical design alternatives, guidance and navigation strategies, and dynamical and orbital simulations.

  • 18. Janhunen, P.
    et al.
    Toivanen, P.K.
    Polkko, J.
    Merikallio, S.
    Salminen, P.
    Haeggström, E.
    Seppänen, H.
    Kurppa, R.
    Ukkonen, J.
    Kiprich, S.
    Thornell, Greger
    Uppsala University, Disciplinary Domain of Science and Technology, Technology, Department of Engineering Sciences, Microsystems Technology.
    Kratz, Henrik
    Richter, L.
    Krömer, O.
    Roste, R.
    Noorma, M.
    Envall, J.
    Lätt, S.
    Mengali, G.
    Quarta, A.
    Koivisto, H.
    Tarvainen, O.
    Kalvas, T.
    Kauppinen, J.
    Nuottajärvi, A.
    Obraztsov, A.
    Electric solar wind sail in.scpace propulsion status report2010In: Proceedings of Space Propulsion, 2010, San Sebastian, Spain, May 3-6, 2010, 2010Conference paper (Refereed)
  • 19.
    Janhunen, Pekka
    et al.
    Finnish Meteorological Institute.
    Merikallio, Sini
    Finnish Meteorological Institute.
    Toivanen, Petri
    Finnish Meteorological Institute.
    Polkko, Jouni
    Finnish Meteorological Institute.
    Haeggström, Edward
    University of Helsinki, Department of Physics.
    Seppänen, Henri
    University of Helsinki, Department of Physics.
    Kurppa, Ristp
    University of Helsinki, Department of Physics.
    Ukkonen, Jukka
    University of Helsinki, Department of Physics.
    Ylitalo, Tuomo
    University of Helsinki, Department of Physics.
    Kiprich, Sergiy
    National Science Center Kharkov Institute of Physics and Technology.
    Koivisto, Hannu
    University of Jyväskylä, Accelerator Laboratory.
    Kalvas, Taneli
    University of Jyväskylä, Accelerator Laboratory.
    Tarvainen, Olli
    University of Jyväskylä, Accelerator Laboratory.
    Kauppinen, Janne
    University of Jyväskylä, Accelerator Laboratory.
    Thornell, Greger
    Uppsala University, Disciplinary Domain of Science and Technology, Technology, Department of Engineering Sciences, Microsystems Technology.
    Kratz, Henrik
    Uppsala University, Disciplinary Domain of Science and Technology, Technology, Department of Engineering Sciences, Microsystems Technology.
    Sundqvist, Johan
    Uppsala University, Disciplinary Domain of Science and Technology, Technology, Department of Engineering Sciences, Microsystems Technology.
    Grönland, Tor-Arne
    Johansson, Håkan
    Rangsten, Pelle
    Vinterhav, Emil
    Noorma, Mart
    University of Tartu.
    Envall, Jouni
    University of Tartu.
    Lätt, Silver
    University of Tartu.
    Allik, Viljo
    University of Tartu.
    Voormansik, Kaupo
    University of Tartu.
    Kvell, Urmas
    Lebreton, Jean-Pierre
    Hallikainen, Martti
    Aalto University.
    Praks, Jaan
    Aalto University.
    Krömer, Olaf
    Rosta, Roland
    Salminen, Pekka
    Mengali, Giovanni
    University of Pisa.
    Quarta, Alessandro
    University of Pisa.
    Aliasi, Generoso
    University of Pisa.
    Marcuccio, Salvo
    Pergola, Pierpaolo
    Giusti, Nicola
    Electric Solar Wind Sail in tailwind2011In: EPSC-DPS Joint Meeting 2011, 2011Conference paper (Refereed)
    Abstract [en]

    The Electric Solar Wind Sail (E-sail) is a novelpropulsion concept that enables faster space travel tomany solar system targets. E-sail uses charged solarwind particles as the source of its propulsion. This isachieved by deploying long, conducting and chargedtethers, which get pushed by the solar wind byCoulomb drag [1].E-sail technology is being developed to technicalreadiness level (TRL) 4-5 by the European Union’sSeventh Framework Programme for Research andTechnological Development, EU FP7, in a projectnamed ESAIL (http://www.electric-sailing.fi/fp7).Prototypes of the key parts are to be produced. Thedesign will be scalable so that a real solar winddemonstration mission could be scaled up from them.We review here the latest results of the constantlyevolving E-sail project.

  • 20.
    Janhunen, Pekka
    et al.
    Finnish Meteorological Institute.
    Toivanen, Petri
    Finnish Meteorological Institute.
    Merikallio, Sini
    Finnish Meteorological Institute.
    Polkko, Jouni
    Finnish Meteorological Institute.
    Haeggström, Edward
    University of Helsinki, Department of Physics.
    Seppänen, Henri
    University of Helsinki, Department of Physics.
    Kurppa, Risto
    University of Helsinki, Department of Physics.
    Ukkonen, Jukka
    University of Helsinki, Department of Physics.
    Ylitalo, Tuomo
    University of Helsinki, Department of Physics.
    Kiprich, Sergiy
    National Science Center Kharkov Institute of Physics and Technology.
    Koivisto, Hannu
    University of Jyväskylä, Accelerator Laboratory.
    Kalvas, Taneli
    University of Jyväskylä, Accelerator Laboratory.
    Tarvainen, Olli
    University of Jyväskylä, Accelerator Laboratory.
    Kauppinen, Janne
    University of Jyväskylä, Accelerator Laboratory.
    Thornell, Greger
    Uppsala University, Disciplinary Domain of Science and Technology, Technology, Department of Engineering Sciences, Microsystems Technology.
    Kratz, Henrik
    Uppsala University, Disciplinary Domain of Science and Technology, Technology, Department of Engineering Sciences, Microsystems Technology.
    Sundqvist, Johan
    Uppsala University, Disciplinary Domain of Science and Technology, Technology, Department of Engineering Sciences, Microsystems Technology.
    Grönland, Tor-Arne
    Johansson, Håkan
    Rangsten, Pelle
    Vinterhav, Emil
    Noorma, Mart
    University of Tartu.
    Envall, Jouni
    University of Tartu.
    Lätt, Silver
    University of Tartu.
    Allik, Viljo
    University of Tartu.
    Voormansik, Kaupo
    University of Tartu.
    Kvell, Urmas
    Lebreton, Jean-Pierre
    Hallikainen, Martti
    Aalto University.
    Praks, Jaan
    Aalto University.
    Krömer, Olaf
    Rosta, Roland
    Salminen, Pekka
    Mengali, Giovanni
    University of Pisa.
    Quarta, Alessandro
    University of Pisa.
    Aliasi, Generoso
    University of Pisa.
    Marcuccio, Salvo
    Pergola, Pierpaolo
    Giusti, Nicola
    Electric Solar Wind Sail Propulsion System Development2011In: International Electric Propulsion Conference, 2011Conference paper (Refereed)
  • 21.
    Jonsson, Jonas
    et al.
    Uppsala University, Disciplinary Domain of Science and Technology, Technology, Department of Engineering Sciences, Microsystems Technology.
    Berglund, Martin
    Uppsala University, Disciplinary Domain of Science and Technology, Technology, Department of Engineering Sciences, Microsystems Technology.
    Kratz, Henrik
    Uppsala University, Disciplinary Domain of Science and Technology, Technology, Department of Engineering Sciences, Microsystems Technology.
    Nguyen, Hugo
    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 compact projection system enabling topographical measurements for a miniaturized submersible explorer2011In: Proceedings of the 16th International Conference on Solid-State Sensors, Actuators and Microsystems (TRANSDUCERS), 2011, IEEE conference proceedings, 2011, p. 2518-2521Conference paper (Refereed)
    Abstract [en]

    To enable photogrammetry of underwater images using a miniaturized submersible explorer, a compact projection system has been developed. By registering the deformation of a known projected pattern, using a laser and a diffractive optical element (DOE), the distance to, shape and size of an object can be calculated. The DOE has been designed, using in-house developed software, and manufactured using microstructure technology. Distances to objects 45 to 30 cm away were determined to within 0.5 cm, and the developed GUI was able to recreate the shape from the measurements for easier examination of the object.

  • 22.
    Jonsson, Jonas
    et al.
    Uppsala University, Disciplinary Domain of Science and Technology, Technology, Department of Engineering Sciences, Microsystems Technology.
    Berglund, Martin
    Uppsala University, Disciplinary Domain of Science and Technology, Technology, Department of Engineering Sciences, Microsystems Technology.
    Kratz, Henrik
    Uppsala University, Disciplinary Domain of Science and Technology, Technology, Department of Engineering Sciences, Microsystems Technology.
    Nguyen, Hugo
    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 compact system to extract topography information from scenes viewed by a miniaturized submersible explorer2012In: Sensors and Actuators A-Physical, ISSN 0924-4247, E-ISSN 1873-3069, Vol. 188, no SI, p. 401-410Article in journal (Refereed)
    Abstract [en]

    In images taken underwater, it is generally difficult to correctly extract distances and geometric informationof objects. Different techniques, collectively referred to as photogrammetry, exist to measurefeatures in images. One of these is to project a reference pattern onto an object in a scene viewed by acamera, and register the distortion of this pattern, to calculate the shape of, and distance to, that object.This method is implemented here on a miniaturized submersible explorer equipped with, among manyother instruments, a camera. Diffractive optical elements (DOEs) have been designed and manufacturedusing microsystems technology, to, together with a laser diode, camera, and in-house developed software,provide a compact system for projecting reference patterns and analyzing their deformations. Thesystem has been characterized by measuring the distances and angles of objects in a water tank, andattempting to reproduce their shapes. The range of operation of the system, verified to be at least onemeter, is limited by the compact mounting in the small submersible and the cameras’ performance.The system was found to work well under turbid conditions as well as in water containing larger particles.Together with a vehicle-mounted camera, the compact and low-power DOE laser projection systemenables topographical measurement.

  • 23.
    Jonsson, Jonas
    et al.
    Uppsala University, Disciplinary Domain of Science and Technology, Technology, Department of Engineering Sciences, Microsystems Technology.
    Edqvist, Erik
    Uppsala University, Disciplinary Domain of Science and Technology, Technology, Department of Engineering Sciences, Microsystems Technology.
    Kratz, Henrik
    Uppsala University, Disciplinary Domain of Science and Technology, Technology, Department of Engineering Sciences, Microsystems Technology.
    Almqvist, Monica
    Electrical Measurements, Lund University.
    Thornell, Greger
    Uppsala University, Disciplinary Domain of Science and Technology, Technology, Department of Engineering Sciences, Microsystems Technology.
    Simulation and Evaluation of Small High-Frequency Side Scan Sonars Using COMSOL2009In: COMSOL Conference 2009 Milan, 2009Conference paper (Other academic)
    Abstract [en]

    High frequency side-scan sonar, to be fitted on a miniaturized submersible explorer, have been simulated and built. The purpose of this study is to see if COMSOL Multiphysics can be used to predict the performance of the sonar, especially the beam width, setting the resolution of the system. Four models were created, from simple 2-D geometries to more complex 3-D models. The simulated beam widths were compared with measurements to see which of the models agreed best. It was found that all models agree with the experimental results to varying degrees, and mostly with a difference of less than 6%. . It was found that the simplest model agreed best with the measurements, closely followed by the most complex model. Also taking the computational load into consideration the simpler model might then be a better choice to use.

  • 24.
    Jonsson, Jonas
    et al.
    Uppsala University, Disciplinary Domain of Science and Technology, Technology, Department of Engineering Sciences, Microsystems Technology.
    Edqvist, Erik
    Uppsala University, Disciplinary Domain of Science and Technology, Technology, Department of Engineering Sciences, Micro Structural Technology.
    Kratz, Henrik
    Uppsala University, Disciplinary Domain of Science and Technology, Technology, Department of Engineering Sciences, Microsystems Technology.
    Almqvist, Monica
    Electrical Measurements, Lund University.
    Thornell, Greger
    Uppsala University, Disciplinary Domain of Science and Technology, Technology, Department of Engineering Sciences, Microsystems Technology.
    Simulation, manufacturing, and evaluation of a sonar for a miniaturized submersible explorer2010In: IEEE Transactions on Ultrasonics, Ferroelectrics and Frequency Control, ISSN 0885-3010, E-ISSN 1525-8955, Vol. 57, no 2, p. 490-495Article in journal (Refereed)
    Abstract [en]

    Single-beam side-scan sonar elements, to be fitted on a miniaturized submersible, are here simulated, manufactured, and evaluated. Finite element analysis simulations are compared with measurements, and an overall observation is that the agreement between simulations and measurements deviates from the measured values of 1.5 to 2°, for the narrow lobe angle, by less than 10% for most models. An overall finding is that the lobe width along the track direction can be accurately simulated and, hence, the resolution of the sonars can be predicted. This paper presents, to the authors’ knowledge, the world’s smallest side-scan sonars.

  • 25.
    Jonsson, Jonas
    et al.
    Uppsala University, Disciplinary Domain of Science and Technology, Technology, Department of Engineering Sciences, Microsystems Technology.
    Lekholm, Ville
    Uppsala University, Disciplinary Domain of Science and Technology, Technology, Department of Engineering Sciences, Microsystems Technology.
    Kratz, Henrik
    Uppsala University, Disciplinary Domain of Science and Technology, Technology, Department of Engineering Sciences, Microsystems Technology.
    Monica, Almqvist
    Dept of Measurement Technology and Industrial Electrical Engineering, Lund University.
    Thornell, Greger
    Uppsala University, Disciplinary Domain of Science and Technology, Technology, Department of Engineering Sciences, Microsystems Technology.
    Enclosure-Induced Interference Effects in a Miniaturized Sidescan Sonar2012In: IEEE Journal of Oceanic Engineering, ISSN 0364-9059, E-ISSN 1558-1691, Vol. 37, no 2, p. 236-243Article in journal (Refereed)
    Abstract [en]

    On, for instance, the miniaturized submersible explorer, Deeper Access, Deeper Understanding (DADU), only 20 cm in length and 5 cm in diameter, the sidescan sonar needs to be tightly mounted in the hull. Finite element analysis (FEA) as well as physical measurements were used to investigate the effects of beam interaction with acoustically nearby rigid boundaries. Computer simulations showed the first major dip in the beam shape to vary in strength, size, and position with the enclosure wall height, from a position of 47° at 0.0-mm wall height to 32° at 3.0-mm wall height. Hydrophonic measurements on the manufactured test device confirmed these values to within 9%, varying between 47° and 29°. In addition, Schlieren imaging was proposed and used as a noninvasive means of qualitative beam shape characterization. A field test was performed with the enclosure height set to 0 and 3 mm. With the latter height, a dark band, corresponding to a sonar sensitivity dip at about 30° in the beam, appeared in the sonar image. It was found that the beam shape is sensitive to small mounting errors, in this case where the wavelength of the sonar is on the same size scale as the enclosure. Furthermore, it was found that FEA models can be used to accurately predict enclosure effects on sonar beam shapes, and Schlieren imaging can be used to visually detect the shape deformations in mounted sonar devices.

  • 26.
    Jonsson, Jonas
    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.
    Johansson, Linda
    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.
    Thornell, Greger
    Uppsala University, Disciplinary Domain of Science and Technology, Technology, Department of Engineering Sciences, Microsystems Technology.
    Acoustically enriching, large-depth aquatic sampler2012In: Lab on a Chip, ISSN 1473-0197, E-ISSN 1473-0189, Vol. 12, no 9, p. 1619-1628Article in journal (Refereed)
    Abstract [en]

    In marine biology, it is useful to collect water samples when exploring the distribution and diversity of microbial communities in underwater environments. In order to provide, e.g., a miniaturized submersible explorer with the capability of collecting microorganisms, a compact sample enrichment system has been developed. The sampler is 30 mm long, 15 mm wide, and just a few millimetres thick. Integrated in a multilayer steel, polyimide and glass construction is a microfluidic channel with piezoelectric transducers, where microorganism and particle samples are collected and enriched, using acoustic radiation forces for gentle and labelless trapping. High-pressure, latchable valves, using paraffin as the actuation material, at each end of the microfluidic channel keep the collected sample pristine. A funnel structure raised above the surface of the device directs water into the microfluidic channel as the vehicle propels itself or when there is a flow across its hull. The valves proved leak proof to a pressure of 2.1 MPa for 19 hours and momentary pressures of 12.5 MPa, corresponding to an ocean depth of more than 1200 metres. By reactivating the latching mechanism, small leakages through the valves could be remedied, which could thus increase the leak-less operational time. Fluorescent particles, 1.9 µm in diameter, were successfully trapped in the microfluidic channel at flow rates up to 15 ml min-1, corresponding to an 18.5 cm s-1 external flow rate of the sampler. In addition, liquid-suspended GFP-marked yeast cells were successfully trapped.

  • 27.
    Jonsson, Jonas
    et al.
    Uppsala University, Disciplinary Domain of Science and Technology, Technology, Department of Engineering Sciences, Microsystems Technology.
    Smedfors, Katarina
    Uppsala University, Disciplinary Domain of Science and Technology, Technology, Department of Engineering Sciences, Microsystems Technology.
    Nyholm, Leif
    Uppsala University, Disciplinary Domain of Science and Technology, Chemistry, Department of Chemistry - Ångström, Inorganic Chemistry.
    Thornell, Greger
    Uppsala University, Disciplinary Domain of Science and Technology, Technology, Department of Engineering Sciences, Microsystems Technology.
    Towards chip-based salinity measurements for small submersibles and biologgers2013In: International Journal of Oceanography, ISSN 1687-9406, E-ISSN 1687-9414, Vol. 2013, p. 529674-Article in journal (Refereed)
    Abstract [en]

    Water’s salinity plays an important role in the environment. It can be determined by measuring conductivity, temperature, anddepth (CTD). The corresponding sensor systems are commonly large and cumbersome. Here, a 7.5 × 3.5mm chip, containingmicrostructured CTD sensor elements, has been developed. On this, 1.5mm2 gold finger electrodes are used to measure theimpedance, and thereby the conductivity of water, in the MHz frequency range. Operation at these frequencies resulted in highersensitivities than those at sub-MHz frequencies. Up to 14 kΩ per parts per thousand salt concentration was obtained repeatedlyfor freshwater concentrations.This was three orders of magnitude higher than that obtained for concentrations in and above thebrackish range. A platinumelectrode is used to determine a set ambient temperature with an accuracy of 0.005∘C.Membranes withNichrome strain gauges responded to a pressure change of 1 bar with a change in resistance of up to 0.21Ω. A linear fit to data over7 bars gave a sensitivity of 0.1185Ω/bar with an R2 of 0.9964. This indicates that the described device can be used in size-limitedapplications, like miniaturized submersibles, or as a bio-logger on marine animals.

  • 28.
    Jonsson, Jonas
    et al.
    Uppsala University, Disciplinary Domain of Science and Technology, Technology, Department of Engineering Sciences, Microsystems Technology.
    Sundqvist, Johan
    Uppsala University, Disciplinary Domain of Science and Technology, Technology, Department of Engineering Sciences, Microsystems Technology.
    Nguyen, Hugo
    Uppsala University, Disciplinary Domain of Science and Technology, Technology, Department of Engineering Sciences, Microsystems Technology.
    Berglund, Martin
    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.
    Palmer, Kristoffer
    Uppsala University, Disciplinary Domain of Science and Technology, Technology, Department of Engineering Sciences, Microsystems Technology.
    Smedfors, Katarina
    Uppsala University, Disciplinary Domain of Science and Technology, Technology, Department of Engineering Sciences, Microsystems Technology.
    Johansson, Linda
    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.
    Thornell, Greger
    Uppsala University, Disciplinary Domain of Science and Technology, Technology, Department of Engineering Sciences, Microsystems Technology.
    Instrumentation and vehicle platform of a miniaturized submersible for exploration of terrestrial and extraterrestrial aqueous environments2012In: Acta Astronautica, ISSN 0094-5765, E-ISSN 1879-2030, Vol. 79, p. 203-211Article in journal (Refereed)
    Abstract [en]

    An example of an extraterrestrial environment likely to support life is the vast liquid body believed to hide underneath the frozen crust of Jupiter's moon Europa. The hypothetical exploration of this, as well as the more accessible subglacial lakes on Earth, has been used as model applications for the development of a heavily miniaturized, yet qualified, submersible with the potential to be deployable either in itself through a long and narrow borehole or as the daughter craft of an ice-penetrating cryobot.

    Onboard the submersible, which is only 20 cm in length and 5 cm in diameter, accommodation of a versatile set of sensors and instruments capable of characterizing and imaging the surroundings, and even collecting water samples with microorganisms for return, is facilitated through the use of miniaturization technologies. For instance, together with a small camera, a laser-based, microoptic device enables the 3-D reconstruction of imaged objects for topographical measurements. As a complement, when the water is turbid or a longer range is wanted, the world's smallest side-scanning sonar, exhibiting centimeter resolution and a range of over 30 m, has been developed. The work on miniaturizing a CTD, which is a widely employed oceanographic instrument used to measure and correlate conductivity, temperature, and depth, has commenced. Furthermore, a device employing acoustics to trap microscopic particles and organisms, and, by this, enrich water samples, is under development. To ensure that the gathered samples are pristine until analyzed at the end of a mission, the device is equipped with high-pressure, latchable valves.

    Remote operation and transfer of measurement data and images, or even live streaming of video, is made possible through a kilometer-long fiber optic cable being reeled out from the vehicle underway and tethering it to a terminal. To extend the missions, the same fiber shall also be capable of charging the onboard batteries.

    In this paper, the vehicle and its subsystems are summarized. Subsystems essential for the vehicle's operation, e.g., hull structure, communication and power management, are treated separately from those of more mission-specific nature, like the instruments mentioned above.

  • 29.
    Jonsson, Jonas
    et al.
    Uppsala University, Disciplinary Domain of Science and Technology, Technology, Department of Engineering Sciences, Microsystems Technology.
    Sundqvist, Johan
    Uppsala University, Disciplinary Domain of Science and Technology, Technology, Department of Engineering Sciences, Microsystems Technology.
    Nguyen, Hugo
    Uppsala University, Disciplinary Domain of Science and Technology, Technology, Department of Engineering Sciences, Microsystems Technology.
    Kratz, Henrik
    Uppsala University, Disciplinary Domain of Science and Technology, Technology, Department of Engineering Sciences, Microsystems Technology.
    Berglund, Martin
    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.
    Palmer, Kristoffer
    Uppsala University, Disciplinary Domain of Science and Technology, Technology, Department of Engineering Sciences, Microsystems Technology.
    Smedfors, Katarina
    Uppsala University, Disciplinary Domain of Science and Technology, Technology, Department of Engineering Sciences, Microsystems Technology.
    Wagner, Sven
    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.
    Thornell, Greger
    Uppsala University, Disciplinary Domain of Science and Technology, Technology, Department of Engineering Sciences, Microsystems Technology.
    Miniaturized submersible for exploration of aqueous environments on Earth and beyond2011Conference paper (Refereed)
    Abstract [en]

    Some of the most likely environments to support extraterrestrial life in our solar system are the ice-covered moons, suchas Europa, thought to harbor a liquid ocean underneath its frozen crust. Exploration, however, necessitates an ice-penetratingcryobot, or a long and narrow borehole, and the subsequent deployment of a small submersible, a hydrobot, with severe sizerestrictions imposed on its scientific payload. As a stepping stone for exploration of such environments, a small instrumentladenedsubmersible vehicle is currently under development.Employment of a large set of instruments capable of characterizing the aqueous environment, imaging the surroundingsand collecting microorganisms is essential for the determination of habitability. Despite the submersible being only 20 cm inlength and 5 cm in diameter, a high degree of functionality is facilitated here through the use of miniaturization technologies. Forinstance, a compact laser-illuminated diffractive optical element, paired with a high-resolution camera, enable photogrammetryand the reconstruction of objects’ shapes in 3-D space. Also for imaging, the world’s smallest side-scanning sonar has beendeveloped to acoustically image, either where water is too turbid for the camera, or where longer range is necessary. Currently,the sonar exhibits centimeter resolution and ranges over 30 meters. On the sensor side, a most vital oceanographic instrument, theCTD, used to measure the conductivity, temperature, and depth of water, has been heavily miniaturized and preliminaryevaluated. Additionally, a water sampler combining integrated selection and enriching capabilities to filter out and accommodate,e.g., microbes in the size range of 1-10 μm, is under development. Among other parts, its high-pressure valves and microfluidicacoustic traps have already been realized.For remote operation and upload of measurement data or images, or even live streaming of video, the submersible will betethered with a bi-directionally transmitting fiber optic cable, also capable of charging the onboard batteries for long missions.The one kilometer long fiber will be fitted within the hull, and by reeling out the fiber from the submersible, drag will be reduced.Herein, test results and images of the vehicle and its complete, and continuously developed, subsystems are presented.The vehicle, and its subsystems as stand-alone instruments, will enable the exploration of previously unreachable analogenvironments on Earth, vital to the field of astrobiology, and act as a forerunner to a submersible hydrobot that can explore icecoveredoceans elsewhere in our solar system.

  • 30.
    Jonsson, Jonas
    et al.
    Uppsala University, Disciplinary Domain of Science and Technology, Technology, Department of Engineering Sciences, Microsystems Technology.
    Sundqvist, Johan
    Uppsala University, Disciplinary Domain of Science and Technology, Technology, Department of Engineering Sciences, Microsystems Technology.
    Nguyen, Hugo
    Uppsala University, Disciplinary Domain of Science and Technology, Technology, Department of Engineering Sciences, Microsystems Technology.
    Kratz, Henrik
    Uppsala University, Disciplinary Domain of Science and Technology, Technology, Department of Engineering Sciences, Microsystems Technology.
    Berglund, Martin
    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.
    Palmer, Kristoffer
    Uppsala University, Disciplinary Domain of Science and Technology, Technology, Department of Engineering Sciences, Microsystems Technology.
    Smedfors, Katarina
    Uppsala University, Disciplinary Domain of Science and Technology, Technology, Department of Engineering Sciences, Microsystems Technology.
    Wagner, Sven
    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.
    Miniaturized submersible for exploration of small aqueous environments2011In: Oceans’11 MTS/IEEE Kona, Hilton Waikoloa Village, Kona, Hawai‘i September 19-22, 2011, 2011Conference paper (Refereed)
    Abstract [en]

    Remotely operated vehicles (ROVs) are commonlyused for sub-surface exploration. However, multi-functionalROVs tend to be fairly large, while preferred small and compactROVs suffer from limited functionality. The Deeper Access,Deeper Understanding (DADU) project aims to develop a smallsubmersible concept using miniaturization technologies to enablea high functionality. An operator is able to maneuver the vehiclewith five degrees of freedom using eight small thrusters, while aset of accelerometers and gyros monitor the orientation of thesubmersible. A single fiber optic cable will connect thesubmersible to a control station and enable simultaneous dataand command transfers. Rechargeable battery packs providepower to the submersibles subsystems during operation. Thesewill be rechargeable through the fiber connection. A forwardlooking camera is aided by a laser topography measurementsystem, where distances, sizes and shapes of objects in view canbe determined to within 0.5 cm. For murkier environments, orwhen a more extensive mapping of the surroundings is needed,the small high-frequency side-scanning sonar can be used.Salinity calculations of the water will be available throughmeasurements of the conductivity, temperature and depth.Samples of water and particles within it will be enabled through awater sampler with an enriching capability. Flow sensors will beable to measure the water movement around the submersible’shull. The submersible and its subsystems are under continuousdevelopment. The vehicle itself, and its subsystems as stand-aloneinstruments, will enable the exploration of previouslyunreachable submerged environments, such as the sub-glaciallakes found in Iceland and Antarctica, or other submerged smallenvironments, such as pipe and cave systems.

  • 31.
    Khaji, Zahra
    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.
    Barbade, Dhananjay
    Uppsala University, Disciplinary Domain of Science and Technology, Technology, Department of Engineering Sciences, Microsystems Technology, Ångström Space Technology Centre (ÅSTC).
    Palmer, Kristoffer
    SSC Nanospace.
    Thornell, Greger
    Uppsala University, Disciplinary Domain of Science and Technology, Technology, Department of Engineering Sciences, Microsystems Technology, Ångström Space Technology Centre (ÅSTC).
    Endurance and Failure of an Alumina-based Monopropellant Microthruster with Integrated Heater, Catalytic Bed and Temperature Sensors2017In: Journal of Micromechanics and Microengineering, ISSN 0960-1317, E-ISSN 1361-6439, Vol. 27, no 5, p. 1-11, article id 055011Article in journal (Refereed)
    Abstract [en]

    Monopropellant ceramic microthrusters with an integrated heater, catalytic bed and two temperature sensors, but of various designs, were manufactured by milling a fluidic channel and chamber, and a nozzle, and screen printing platinum patterns on green tapes of alumina that were stacked and laminated before sintering. In order to increase the surface area of the catalytic bed, the platinum paste was mixed with a sacrificial paste that disappeared during sintering, to leave behind a porous and rough layer. As an early development level in manufacturing robust and high-temperature tolerant microthrusters, the influence of design on the temperature gradients and dry temperature tolerance of the devices was studied. On average, the small reaction chambers showed a more than 1.5 times higher dry temperature tolerance (in centigrade) compared to devices with larger chambers, independent of the heater and device size. However, for a given temperature, big devices consumed on average 2.9 times more power than the small ones. It was also found that over the same area and under the same heating conditions, devices with small chambers were subjected to approximately 40% smaller temperature differences. A pressure test done on two small devices with small chambers revealed that pressures of at least 26.3 bar could be tolerated. Above this pressure, the interfaces failed but the devices were not damaged. To investigate the cooling effect of the micropropellant, the endurance of a full thruster was also studied under wet testing where it was fed with 31 wt.% hydrogen peroxide. The thruster demonstrated complete evaporation and/or full decomposition at a power above 3.7 W for a propellant flow of 50 mu l min(-1). At this power, the catalytic bed locally reached a temperature of 147 degrees C. The component was successfully heated to an operating temperature of 307 degrees C, where it cracked. Under these firing conditions, and assuming complete decomposition, calculations give a thrust and specific impulse of 0.96 mN and 106 s, respectively. In the case of evaporation, the corresponding values are calculated to be 0.84 mN and 92 s.

  • 32.
    Khaji, Zahra
    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.
    Thornell, Greger
    Uppsala University, Disciplinary Domain of Science and Technology, Technology, Department of Engineering Sciences, Microsystems Technology, Ångström Space Technology Centre (ÅSTC).
    Manufacturing and characterization of a ceramic single-use microvalve2016In: Journal of Micromechanics and Microengineering, ISSN 0960-1317, E-ISSN 1361-6439, Vol. 26, no 9, article id 095002Article in journal (Refereed)
    Abstract [en]

    We present the manufacturing and characterization of a ceramic single-use microvalve withthe potential to be integrated in lab-on-a-chip devices, and forsee its utilization in space andother demanding applications. A 3 mm diameter membrane was used as the flow barrier, andthe opening mechanism was based on cracking the membrane by inducing thermal stresses onit with fast and localized resistive heating.

    Four manufacturing schemes based on high-temperature co-fired ceramic technology werestudied. Three designs for the integrated heaters and two thicknesses of 40 and 120 μmfor the membranes were considered, and the heat distribution over their membranes, therequired heating energies, their opening mode, and the flows admitted through were compared.Furthermore, the effect of applying +1 and −1 bar pressure difference on the membraneduring cracking was investigated. Thick membranes demonstrated unpromising results forlow-pressure applications since the heating either resulted in microcracks or cracking of thewhole chip. Because of the higher pressure tolerance of the thick membranes, the designwith microcracks can be considered for high-pressure applications where flow is facilitatedanyway. Thin membranes, on the other hand, showed different opening sizes depending onheater design and, consequently, heat distribution over the membranes, from microcracks toholes with sizes of 3–100% of the membrane area. For all the designs, applying +1 bar overpressure contributed to bigger openings, whereas −1 bar pressure difference only did so forone of the designs, resulting in smaller openings for the other two. The energy required forbreaking these membranes was a few hundred mJ with no significant dependence on designand applied pressure. The maximum sustainable pressure of the valve for the current designand thin membranes was 7 bar.

  • 33.
    Khaji, Zahra
    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 National Defence College.
    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.
    Thornell, Greger
    Uppsala University, Disciplinary Domain of Science and Technology, Technology, Department of Engineering Sciences, Microsystems Technology.
    Design and fabrication of a miniaturized combustor with integrated oxygen storage and release element2014In: 25th Micromechanics and Microsystems Europe workshop  (MME 2014),2014, P19 (4 pp), 2014Conference paper (Refereed)
    Abstract [en]

    A miniature combustor for converting organic samples into CO2 with application in carbon isotopic measurements of small samples has been manufactured and evaluated. The combustor was made by machining and laminating High-Temperature Co-fired Ceramic (HTCC) 99.99% alumina green tapes and screen printing platinum conductors on them. The device has a built-in heater and a temperature sensor made of platinum, which were co-sintered with the ceramic. A metal oxide (copper oxide) oxygen supply was added to the combustor after sintering by in-situ electroplating of copper on the heater pattern followed by thermal oxidation. Scanning Electron Microscopy (SEM), Energy Dispersive Spectroscopy (EDS) and Thermal Gravimetric Analysis (TGA) were used to study electroplating, oxidation and the oxide decompo-sition processes.

  • 34.
    Khaji, Zahra
    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, Ångström Space Technology Centre (ÅSTC). Swedish National Defence College.
    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.
    Thornell, Greger
    Uppsala University, Disciplinary Domain of Science and Technology, Technology, Department of Engineering Sciences, Microsystems Technology, Ångström Space Technology Centre (ÅSTC).
    Investigation of the storage and release of oxygen in a Cu-Pt element of a high-temperature microcombustor2014In: The 14th International Conference on Micro and Nanotechnology for Power Generation and Energy Conversion Applications(PowerMEMS 2014), Institute of Physics (IOP), 2014Conference paper (Refereed)
    Abstract [en]

    A miniature combustor for converting organic samples into CO2 with application in carbon isotopic measurements has been manufactured and evaluated. The combustor was made of High-Temperature Co-fired Ceramic (HTCC) alumina green tapes. The device has a built-in screen printed heater and a temperature sensor made of platinum, co-sintered with the ceramic. A copper oxide oxygen supply was added to the combustor after sintering by in-situ electroplating of copper on the heater pattern followed by thermal oxidation. Scanning Electron Microscopy (SEM), Energy Dispersive Spectroscopy (EDS) and Thermal Gravimetric Analysis (TGA) were used to study electroplating, oxidation and the oxide reduction processes. The temperature sensor was calibrated by use of a thermocouple. It demonstrates a temperature coefficient resistance of 4.66×10−3/°C between 32 and 660 °C. The heat characterization was done up to 1000 °C by using IR thermography, and the results were compared with the data from the temperature sensor. Combustion of starch confirmed the feasibility of using copper oxide as the source of oxygen of combustion.

  • 35.
    Khaji, Zahra
    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 National Defence College.
    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.
    Thornell, Greger
    Uppsala University, Disciplinary Domain of Science and Technology, Technology, Department of Engineering Sciences, Microsystems Technology.
    Manufacturing and characterization of a ceramic microcombustor with integrated oxygen storage and release element2015In: Journal of Micromechanics and Microengineering, ISSN 0960-1317, E-ISSN 1361-6439, Vol. 25, no 10, article id 104006Article in journal (Refereed)
    Abstract [en]

    A microscale ceramic high-temperature combustor with a built-in temperature sensor and source of oxygen has been designed, manufactured and characterized. The successful in situ electroplating and oxidation of copper, and the use of copper oxide as the source of oxygen were demonstrated. It was shown that residual stresses from electroplating, copper oxidation and oxide decomposition did not cause much deformation of the substrate but influenced mainly the integrity and adhesion of the metal films. The process had influence on the electrical resistances, however. Calibration of the temperature sensor and correlation with IR thermography up to 1000°C revealed a nearly linear sensor behavior. Demonstration of combustion in a vacuum chamber proved that no combustion had occurred before release of oxygen from the metal oxide resource.

  • 36.
    Khaji, Zhara
    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.
    Klintberg, Lena
    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.
    Hjort, Klas
    Uppsala University, Disciplinary Domain of Science and Technology, Technology, Department of Engineering Sciences, Microsystems Technology.
    Extending Microsensor Technology to Very High Temperatures2014Conference paper (Other academic)
  • 37.
    Klintberg, Lena
    et al.
    Uppsala University, Disciplinary Domain of Science and Technology, Technology, Department of Materials Science.
    Karlsson, M
    Stenmark, Lars
    Schweitz, Jan-Åke
    Uppsala University, Disciplinary Domain of Science and Technology, Technology, Department of Materials Science.
    Thornell, Greger
    Uppsala University, Disciplinary Domain of Science and Technology, Technology, Department of Materials Science.
    A large stroke, high force paraffin phase transition actuator2002In: Sensors and Actuators A-Physical, ISSN 0924-4247, E-ISSN 1873-3069, Vol. 96, no 2-3, p. 189-195Article in journal (Refereed)
    Abstract [en]

    An actuator that uses the volume expansion related to the solid-to-liquid phase transition of paraffin wax has been fabricated and evaluated. The actuator consists of a ring-shaped paraffin cavity confined by two joint silicon diaphragms with rigid centers. When the paraffin is melted, the resulting hydrostatic pressure deflects the joined rigid centers in one direction only. The magnitude of the deflection is primarily a function of the geometrical relation between the two diaphragms, giving the opportunity to tailor the behavior of the actuator in a large range. Conventional IC-processing techniques have been used to fabricate a prototype with a width of 68 mm and a thickness of 825 μm. The prototype attained a maximum deflection of ca. 90 μm. Loaded with 3 N it still exhibits a deflection of ca. 75 μm. The device can be used as a thermal switch.

  • 38.
    Klintberg, Lena
    et al.
    Uppsala University, Disciplinary Domain of Science and Technology, Technology, Department of Materials Science.
    Karlsson, M
    Uppsala University, Disciplinary Domain of Science and Technology, Technology, Department of Materials Science.
    Stenmark, Lars
    Uppsala University, Disciplinary Domain of Science and Technology, Technology, Department of Materials Science.
    Thornell, Greger
    Uppsala University, Disciplinary Domain of Science and Technology, Technology, Department of Materials Science.
    A thermally activated paraffin-based actuator for gas-flow control in a satellite electrical propulsion system2003In: Sensors and Actuators A-Physical, ISSN 0924-4247, E-ISSN 1873-3069, Vol. 105, no 3, p. 237-246Article in journal (Refereed)
    Abstract [en]

    Microstructured silicon devices consisting of three inflatable paraffin-filled, corrugated caddies suspended in springs to minimize thermal losses have been fabricated and evaluated with a valve application in mind. The large volume expansion associated with the thermally induced solid-to-liquid phase transition of paraffin is used to activate the caddies’ diaphragms. Theses components all with a thickness of 600 μm and a diameter of 39 mm, but with three different corrugations, have been fabricated with deep reactive etching (DRIE). Whereas the corrugated diaphragms could endure a deflection larger than 50 μm, only strokes of 15 μm on each side were attained when the components were activated. Together with the valve seats proposed, the investigated devices have a potential in electrical propulsion systems for satellites.

  • 39.
    Klintberg, Lena
    et al.
    Uppsala University, Disciplinary Domain of Science and Technology, Technology, Department of Materials Science.
    Lindeberg, Mikael
    Uppsala University, Disciplinary Domain of Science and Technology, Technology, Department of Materials Science.
    Thornell, Greger
    Uppsala University, Disciplinary Domain of Science and Technology, Technology, Department of Materials Science.
    Sodium hypochlorite as a developer for heavy ion tracks in polyimide2001In: Nuclear Instruments and Methods in Physics Research Section B: Beam Interactions with Materials and Atoms, ISSN 0168-583X, E-ISSN 1872-9584, Vol. 184, no 4, p. 536-543Article in journal (Refereed)
    Abstract [en]

    he developing and etching of heavy ion tracks in polyimide with sodium hypochlorite have been studied to gain control over the parameters that affect the etch result. The shape of the resulting pores is a function of both alkalinity and hypochlorite content of the solution. Sodium hypochlorite decomposes during etching, and the rate constant has been determined as a function of the alkalinity at 62 °C. Polished cross-sections have been examined to determine the pore shape, and this method has shown to be a straightforward way to characterise the pores. Decreasing the alkalinity gives more cylindrical pores, but increases the decomposition rate of the hypochlorite solution and decreases the etch rate.

  • 40.
    Klintberg, Lena
    et al.
    Uppsala University, Disciplinary Domain of Science and Technology, Technology, Department of Materials Science.
    Svedberg, Malin
    Uppsala University, Disciplinary Domain of Science and Technology, Technology, Department of Materials Science.
    Nikolajeff, Fredrik
    Uppsala University, Disciplinary Domain of Science and Technology, Technology, Department of Materials Science.
    Thornell, Greger
    Uppsala University, Disciplinary Domain of Science and Technology, Technology, Department of Materials Science.
    Fabrication of a paraffin actuator using hot embossing of polycarbonate2003In: Sensors and Actuators A-Physical, ISSN 0924-4247, E-ISSN 1873-3069, Vol. 103, no 3, p. 307-316Article in journal (Refereed)
    Abstract [en]

    In this paper a fabrication process for integrating paraffin-actuated structures in polycarbonate is outlined. A paraffin-actuated membrane with a diameter of 2.5 mm, where the volume expansion of 10–15% associated with the solid-to-liquid phase transition of paraffin is utilized, has been fabricated and evaluated. Microstructures fabricated in silicon have via an electroplated nickel mould been replicated in polycarbonate by hot embossing and the resulting structures have been sealed by thermal bonding. The bonding strength was measured by a pressurizing test, and the polycarbonate surfaces were characterized with electron spectroscopy for chemical analysis (ESCA). It was found that the bond strength increased when an oxygen plasma treatment was used prior to bonding. ESCA measurements showed a corresponding increase in oxygen content on the plasma treated surfaces. This procedure also improved the wetting properties. The contact angle between paraffin and polycarbonate decreased from 10° after embossing to about 5° after plasma treatment. The fabricated actuator had a total thickness of 1 mm and the membrane deflected about 140 μm when heating the actuator above the melting point of paraffin. Paraffin wax actuators are possible to integrate in plastic structures making them promising candidates in applications such as disposable microfluidic systems where inexpensive and robust valves and pumps are needed.

  • 41.
    Klintberg, Lena
    et al.
    Uppsala University, Disciplinary Domain of Science and Technology, Technology, Department of Materials Science.
    Thornell, Greger
    Uppsala University, Disciplinary Domain of Science and Technology, Technology, Department of Materials Science.
    A thermal microactuator made by partial impregnation of polyimide with paraffin2002In: Journal of Micromechanics and Microengineering, ISSN 0960-1317, E-ISSN 1361-6439, Vol. 12, no 6, p. 849-854Article in journal (Refereed)
    Abstract [en]

    We have fabricated and tested thermal, paraffin-impregnated polyimide actuators, utilizing the large volume increase associated with the solid-to-liquid phase transition of paraffin. In the bimorph-like device, the top layer was made porous by ion track technology. Stochastically distributed pores of various lengths (95, 70, 45 and 20 µm) and various lateral coverages (5–45%) were filled with paraffin by liquid substitution or from vacuum, and sealed with epoxy. Actuators, 125 µm thick, 35 mm long and 7 mm wide, have been characterized with respect to tip deflection and load-carrying capacity with one end rigidly clamped. Loaded with 0.6 g or about ten times their own weight at their free end, about 50% of the maximum stroke (17 mm) was still attained.

  • 42.
    Klintberg, Lena
    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.
    Som man frågar får man svar: studenter formulerar frågor och väljer lärstrategi2015In: 5:e Utvecklingskonferensen för Sveriges ingenjörsutbildningar, Uppsala, 2015Conference paper (Refereed)
    Abstract [sv]

    Blooms taxonomi kategoriserar olika lärstrategierefter komplexitetsgrad. Nybörjare är faktafokuserade eftersomdet är mer krävande att analysera, bedöma och värderakunskaper. Valet av lärstrategi är situationsberoende ochfaktorer som motivation och nyfikenhet leder ofta till ett merkomplext angreppssätt. För att undersöka vad civilingenjörsstudentersom läser näst sista året själva spontant väljerför lärstrategier, fick 43 studenter läsa in ett antal artiklar somett moment i kursen Mikro- och nanoteknik I. Därefter ombadsde formulera frågor på materialet. I ett försök att aktivt påverkade lärstrategier som studenterna valde skulle frågorna bådeberöra sådant studenterna identifierade som värdefull kunskapsamt sådant artiklarna inte gav svar på men som de skulle viljaveta. Studenterna fick sedan klassificera frågorna enligt Bloomstaxonomi. För ett antal utvalda frågor jämfördes därefterklassificeringen med en som lärarkollegiet gjorde och resultatetblev att lärarna tenderade att ranka de enkla frågorna högre ochmer komplicerade frågor lägre jämfört med studenterna. I en uppföljningsstudie undersöktes om studenterna ansåg attuppgiften att själv få formulera frågor gett dem bättreförståelsen och fått dem att fundera mer över materialet jämfört med om de fått instuderingsuppgifter. Resultatet visar att praktiskt taget alla studenter spontantställt minst en fråga som de kategoriserat ibland de högsta komplexitetsnivåerna och som tillsammans täcker de inkomna frågorna de aspekter som lärarkollegiet anser är viktigt imaterialet. Vissa artiklar visade sig stimulera till frågor med högre komplexitet och det fanns ett tydligt samband som visadeatt mer komplexa frågor ställdes då svaren inte fanns imaterialet. Hela 68% av studenterna bedömde att metoden att själva få formulera frågor på materialet givit dem en bättre förståelse jämfört med om de fått färdiga frågor att besvara efter inläsningen. Frågorna visade sig också ge värdefull insikt i vad studenterna funderar på och är nyfikna att veta mer om, t ex aspekter rörande miljö, hälsa och ekonomi.

  • 43.
    Klintberg, Lena
    et al.
    Uppsala University, Disciplinary Domain of Science and Technology, Technology, Department of Engineering Sciences, Microsystems Technology.
    Viberg, Pernilla
    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.
    Förmedling av komplexa begrepp i multidisciplinär kurs på avancerad niv2013Conference paper (Refereed)
    Abstract [sv]

    Vid undervisning på avancerad nivå i en multidisciplinär kurs används och behandlas vanligtvis komplexa begrepp från flera olika ämnesområden. Vid samläsning över olika program, skiljer sig studenternas förkunskaper åt även om studenterna från de olika programmen formellt uppfyller förkunskapskraven. Detta inverkar på studenternas förmåga att tillgodogöra sig kursens innehåll.

    En studie har gjorts på en kurs i mikro- och nanoteknik, som ges under 4:e året på flera olika civilingenjörsprogram. Med anledning av de identifierade skillnaderna, har en undersökning av tidigare studenters erfarenhet av kursen gjorts. Dessutom har de blivande studenternas förkunskaper inventerats och jämförts med de begrepp som används i kursen.

    Resultatet visar att studenterna i kemiteknik i viss utsträckning förfördelats även om skillnaderna är små.

    16% av studenterna som läst teknisk fysik med material­vetenskap (MV) når högsta betyg på kursen jämfört med 10% för studenterna i kemiteknik (KT), men i medelbetyg är det ingen signifikant skillnad mellan studentgrupperna. Vid rankning av påståendet ”Nya begrepp introducerades på ett bra och tydligt sätt” gav MV-studenterna 4,0 i medel medan KT studenterna gav 3,5 på skalan 1 (aldrig) till 5 (alltid). Syftet med denna undersökning är att, utifrån de identifierade skillnaderna, kunna hitta nya sätt att introducera och exemplifiera begreppen så att studentgrupperna får likvärdiga förutsättningar att tillgodogöra sig kursens innehåll.

  • 44.
    Kratz, Henrik
    et al.
    Uppsala University, Disciplinary Domain of Science and Technology, Technology, Department of Engineering Sciences, Microsystems Technology.
    Eriksson, Anders
    Uppsala University, Disciplinary Domain of Science and Technology, Technology, Department of Engineering Sciences, Microsystems Technology.
    Karlsson, Mikael
    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.
    Thornell, Greger
    Uppsala University, Disciplinary Domain of Science and Technology, Technology, Department of Engineering Sciences, Microsystems Technology.
    Analysis of Thermal Transients in an Asymmetric Silicon-Based Heat Dissipation Stage2007In: IEEE transactions on components and packaging technologies (Print), ISSN 1521-3331, E-ISSN 1557-9972, Vol. 30, no 3, p. 444-456Article in journal (Refereed)
    Abstract [en]

    Thermal management is crucial for many microsystems and electronics applications (and that of miniaturized spacecraft is particularly demanding). This paper presents thermal modeling and scaling of a generic multiwafer silicon segment for placement in between two devices, or as a stage for a single one, in need of asymmetric thermal management. The unit is autonomous, i.e., it doesn't require any input signals or power. It comprises paraffin acting both as a heat sink, or thermal storage, and a material activating heat switches. The former mitigates heat bursts and accommodates power initially generated in, e.g., attached electronics, whereas the latter facilitates heat dissipation through heat guides during more intensive operation. Its function and physical properties are described in detail. A lumped thermal model has been constructed and implemented in the Simulink environment to investigate effects from: physical scaling of the unit, and change of its boundary temperature and coupling thereto, power generated, its emission and absorption properties and area fractions dedicated for passive devices, infrared (IR) emission, and heat guides on the unit's exterior, as well as fractional cross sections of paraffin, heat guides and other structural material in its interior. Conclusions, based on simulation results, are made and design rules based on the thermal modeling are presented. It was found that a 68 times 68 mm module could handle more than 10 W for 6 min in its heat sink mode alone. Subjected to 15 W for the same time, the module enters its active dissipation mode by closing its heat switches. A lateral increase and simultaneous vertical decrease of the unit's size resulted in overheating, whereas most scaling did not cause depletion of the heat sink. Changing the area fractions of various constituents also indicated operational stability with exception for excessive enlargement of passive heat guide material, exchanging structural material with paraffin, - or severely limiting IR emission (by emitter area reduction or using low emission material), or using high absorbance material. Altering the boundary temperature and interface conductance proved to be means of biasing the system to various operating temperatures.

  • 45.
    Kratz, Henrik
    et al.
    Uppsala University, Disciplinary Domain of Science and Technology, Technology, Department of Engineering Sciences, Microsystems Technology, Ångström Space Technology Centre (ÅSTC).
    Karlsson, Mikael
    Uppsala University, Disciplinary Domain of Science and Technology, Technology, Department of Engineering Sciences, Microsystems Technology, Ångström Space Technology Centre (ÅSTC).
    Eriksson, Anders
    Uppsala University, Disciplinary Domain of Science and Technology, Technology, Department of Engineering Sciences, Microsystems Technology, Ångström Space Technology Centre (ÅSTC).
    Köhler, Johan
    Uppsala University, Disciplinary Domain of Science and Technology, Technology, Department of Engineering Sciences, Microsystems Technology, Ångström Space Technology Centre (ÅSTC).
    Stenmark, Lars
    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).
    Design and Modeling of a thermally regulated communications module for nanospacecraft2006In: Journal of Spacecraft and Rockets, ISSN 0022-4650, E-ISSN 1533-6794, Vol. 43, no 6, p. 1377-1386Article in journal (Refereed)
    Abstract [en]

    A silicon-based integrated communications and thermal management microsystem qualifying for use on Nanospace-1, a modularized microsystem-based advanced integrated nanospacecraft, is presented. The transmitter and receiver share the same module framework with essential differences only in the electronics implementation. A data rate of 1 Mbps for the transmitter and 114 kbps for the receiver is accomplished with a transmitter power for the spacecraft and ground station of 2 and 10 W, respectively. Concurrent triple usage of paraffin as low loss antenna substrate, actuator material, and heat sink is designed and analyzed for the first time. On low-power or short-time high-power dissipation of heat from the electronics, energy is stored as latent heat in this phase-change material acting as a heat sink. Thermal transport through the module is initiated,by actuation of thermal switches when 75% of the paraffin's latent heat is consumed. A static thermal analysis reveals a thermal modulation factor of 5.6 between the on and off states of the thermal switches. The size of the module is 6.6 x 68 x 68 mm, and its weight is 43 g.

  • 46. Köhler, Johan
    et al.
    Kratz, Henrik
    Uppsala University, Disciplinary Domain of Science and Technology, Technology, Department of Engineering Sciences, Microsystems Technology.
    Nguyen, Hugo
    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.
    Modular Multifunctional Silicon Microsystems for Spacecraft Applications2007Conference paper (Refereed)
  • 47.
    Lehto, Marcus
    et al.
    Uppsala University, Disciplinary Domain of Science and Technology, Technology, Department of Engineering Sciences, Division for Electricity and Lightning Research.
    Bodén, Roger
    Uppsala University, Disciplinary Domain of Science and Technology, Technology, Department of Engineering Sciences, Micro Structural Technology.
    Simu, Urban
    Uppsala University, Disciplinary Domain of Science and Technology, Technology, Department of Engineering Sciences, Micro Structural Technology.
    Hjort, Klas
    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.
    Schweitz, Jan-Åke
    Uppsala University, Disciplinary Domain of Science and Technology, Technology, Department of Engineering Sciences, Microsystems Technology.
    A polymeric paraffin microactuator2008In: Journal of microelectromechanical systems, ISSN 1057-7157, E-ISSN 1941-0158, Vol. 17, no 5, p. 1172-1177Article in journal (Refereed)
    Abstract [en]

    Paraffin wax is a promising material in microactuators not only because of its ability of producing large displacements and high forces at the same time but also because of the variety of manufacturing techniques available. In this paper, a simple actuator based on paraffin wax as the active material is fabricated and tested. Ultraviolet-curable epoxy is used in a technique combining simultaneous moulding and liquid-phase photopolymerization in a single-process step to build the stiff part of the actuator body. A heater is integrated in the paraffin reservoir, and a polyimide tape is used as the deflecting membrane. Thermornechanical analysis of the paraffin wax shows that it exhibits a volume expansion of 10%, including phase transitions and linear expansion. As for the actuator, a stroke of 90 mu m is obtained for the unloaded device, whereas 37 mu m is recorded with a 0.5-N contact load at a driving voltage of 0.71 V and a frequency of 1/32 Hz. The actuator can be used in microsystems, where both large strokes and forces are needed. The low-cost materials and low driving voltage also makes it suitable for disposable systems.

  • 48.
    Lehto, Marcus
    et al.
    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.
    Simu, Urban
    Hjort, Klas
    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.
    Schweitz, Jan-Åke
    Uppsala University, Disciplinary Domain of Science and Technology, Technology, Department of Engineering Sciences, Microsystems Technology.
    Rapid prototyping of a polymeric paraffin microactuator2008In: Journal of microelectromechanical systems, ISSN 1057-7157, E-ISSN 1941-0158, Vol. 17, no 5, p. 1172-1177Article in journal (Refereed)
    Abstract [en]

    Paraffin wax is a promising material in microactuators not only because of its ability of producing large displacements and high forces at the same time but also because of the variety of manufacturing techniques available. In this paper, a simple actuator based on paraffin wax as the active material is fabricated and tested. Ultraviolet-curable epoxy is used in a technique combining simultaneous moulding and liquid-phase photopolymerization in a single-process step to build the stiff part of the actuator body. A heater is integrated in the paraffin reservoir, and a polyimide tape is used as the deflecting membrane. Thermomechanical analysis of the paraffin wax shows that it exhibits a volume expansion of 10%, including phase transitions and linear expansion. As for the actuator, a stroke of 90 mum is obtained for the unloaded device, whereas 37 mum is recorded with a 0.5-N contact load at a driving voltage of 0.71 V and a frequency of 1/32 Hz. The actuator can be used in microsystems, where both large strokes and forces are needed. The low-cost materials and low driving voltage also makes it suitable for disposable systems.

  • 49.
    Lehto, Marcus
    et al.
    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.
    Thornell, Greger
    Uppsala University, Disciplinary Domain of Science and Technology, Technology, Department of Engineering Sciences, Microsystems Technology.
    Binary mixtures of n-alkanes for tunable thermohydraulic microactuators2007In: Journal of microelectromechanical systems, ISSN 1057-7157, E-ISSN 1941-0158, Vol. 16, no 3, p. 728-733Article in journal (Refereed)
    Abstract [en]

    The two objectives of this paper are related to the use of n-alkanes in actuators. The first objective is to study the thermomechanics of binary mixtures of dotriacontane and hexatriacontane to see if a quasi-stable thermal expansion can be obtained, and the second one is to find the correspondence between dilatometry [pressure, volume, and temperature (pVT) measurement] and differential scanning calorimetry (DSC). Results show that there is indeed a concentration-dependent plateau in the expansion curves and that the width and horizontal position of this can be adjusted. As compared with pure n-alkanes, the plateaus of the mixtures widen by a factor of 2-4, and as compared with pure hexatriacontane, they shift their low-end temperatures by 5 °C to 10 °C, in the 25% to 75% concentration range. The mixtures' plateaus (gathered around 0.06 cm3/g) are about 0.02 cm3/g below those of the pure n-alkanes. It is shown that DSC can be used for a prediction of the thermomechanical properties of the substances, provided that a pVT reference exists, and the fact that the melting point increases with the pressure that is experienced with the dilatometer is considered. The qualitative similarity between the expansion and enthalpy curves is remarkable. About 25% to 30% of the total volume expansion is attributed to the solid-to-solid phase transition; the rest is attributed to thermal expansion and melting.

  • 50.
    Lekholm, Ville
    et al.
    Uppsala University, Disciplinary Domain of Science and Technology, Technology, Department of Engineering Sciences, Microsystems Technology.
    Ericson, Fredric
    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.
    Greger, Thornell
    Uppsala University, Disciplinary Domain of Science and Technology, Technology, Department of Engineering Sciences, Microsystems Technology.
    Ceramic microcomponents for high-temperature fluidics2010In: Technical DigestPowerMEMS 2010, The 10th International Workshop on Micro and Nanotechnology for Power Generation and Energy Conversion Applications, Leuven, Belgium, December 1-3, 2010: Poster Sessions, 2010, p. 291-294Conference paper (Refereed)
    Abstract [en]

    For aggressive environments, the material properties of silicon become a limitation. Macroscopically, ceramics are as abundant for high-temperature applications as is silicon in miniaturized systems, but this group of materials has been little exploited for MEMS components. A major reason is the lack of means for high-resolution structuring. This paper describes the application of silicon-based manufacturing processes in the fabrication of ceramic yet truly micromechanical structures and devices for very high-temperature applications, and demonstrates the technique’s implementation in, and significance for, high-temperature microfluidics. Embossing of structures down to 2 µm wide is demonstrated, as well as deep embossing (50 µm), punching through 15 µm tape, and lamination of structured layers. The resulting samples survive temperatures of 1400ºC.

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