| 1. |
- Enoksson, Peter, 1957, et al.
(författare)
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A Coriolis mass flow sensor structure in silicon
- 1996
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Ingår i: IEEE International Workshop on Micro Electromechanical Systems (1996 MEMS), Feb. 11-15, San Diego, USA.
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Konferensbidrag (refereegranskat)
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| 2. |
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| 5. |
- Enoksson, Peter, 1957, et al.
(författare)
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Microfluid Device Research at KTH
- 1996
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Ingår i: Micro Structure Workshop 1996 (MSW’96), March 26-27, Uppsala, Sweden..
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Konferensbidrag (refereegranskat)
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| 10. |
- Jaouen, Frédéric, et al.
(författare)
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Adhesive copper films for an air-breathing polymer electrolyte fuel cell
- 2005
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Ingår i: Journal of Power Sources. - : Elsevier BV. - 0378-7753 .- 1873-2755. ; 144:1, s. 113-121
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Tidskriftsartikel (refereegranskat)abstract
- A design for an air-breathing and passive polymer electrolyte fuel cell is presented. Such a type of fuel cell is in general promising for portable electronics. In the present design, the anode current collector is made of a thin copper foil. The foil is provided with an adhesive and conductive coating, which firstly tightens the hydrogen compartment without mask or clamping pressure, and secondly secures a good electronic contact between the anode backing and the current collector. The cathode comprises a backing, a gold-plated stainless steel mesh and a current collector cut out from a printed circuit board. Three geometries for the cathode current collector were evaluated. Single cells with an active area of 2 cm(2) yielded a peak power of 250-300 MW cm(-2) with air and pure H-2 in a complete passive mode except for the controlled flow of H-2. The cells' response was investigated in steady state and transient modes.
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| 11. |
- Olsson, Anders, et al.
(författare)
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A valve-less planar pump in silicon
- 1995
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Ingår i: The 8th International Conference on Solid-State Sensors (TRANSDUCERS'95), Stockholm, Sweden, June 25-29. ; , s. 291-294
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Konferensbidrag (refereegranskat)
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| 16. |
- Olsson, Anders, et al.
(författare)
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Numerical and experimental studies of flat-walled diffuser elements for valve-less micropumps
- 2000
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Ingår i: Sensors and Actuators A-Physical. - 0924-4247 .- 1873-3069. ; 84:02-jan, s. 165-175
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Tidskriftsartikel (refereegranskat)abstract
- An investigation of flat-walled diffuser elements for valve-less micropumps is presented. The diffuser element is a small angle flow channel with a rounded inlet and a preferably sharp outlet. The diverging-wall direction is the positive flow direction. The flow-directing capability under steady flow conditions was determined experimentally for several different diffuser elements. The flow-pressure characteristic was studied in detail for one of them. The result is compared with previously published results on pump performance. Numerical simulations were done using the Computational Fluid Dynamics program ANSYS/Flotran. The simulations show the flow-directing capability of the diffuser elements and predict the flow-pressure characteristics well for Reynolds numbers below 300-400. For higher Reynolds numbers, the simulations show the flow-directing capability, but there is a larger discrepancy between simulations and measurements. Simulations were also done for a nozzle element, a wide-angle flow channel with sharp inlet and outlets used in the micropump with dynamic passive-valves. A nozzle element has the converging-wall direction as positive flow direction. The simulations show differences in the flow patterns for diffuser elements and nozzle elements that explain the opposite positive flow directions. The diffuser element has an ordered flow and takes advantage of the pressure recovery in the diverging-wall direction. The nozzle element has gross flow separation in the diverging-wall direction and there is a vena-contracta effect instead of pressure recovery. The effective cross-sectional area is smaller in the diverging-wall direction than in the converging-wall direction.
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| 17. |
- Stemme, Göran, 1958-, et al.
(författare)
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Förträngningspump av membranpumptyp
- 1993
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Patent (populärvet., debatt m.m.)abstract
- A displacement pump with a pump housing containing a pump chamber of varying volume, the limiting walls of which includes a moveable portion or diaphragm, the movement and/or deformation of which varies the pump chamber volume. The pump chamber has a fluid inlet on the suction side of the pump and a fluid outlet on the pressure side. Both the fluid inlet and the fluid outlet, or possibly only one of them, includes a flow controlling element having one diffuser and one diffuser inlet which, for the same flow, has a larger pressure drop in one flow direction (the nozzle direction) than in the opposite flow direction (the diffuser direction). A drive element is coupled to the diaphragm, whereby the diaphragm can be caused to oscillate, so that the fluid volume in the pump chamber is caused to pulsate and thereby produce a net flow of fluid through the pump.
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| 18. |
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| 19. |
- Stemme, Göran, 1958-, et al.
(författare)
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Trycksensor innefattande en tryckkänslig flat kapsel
- 1989
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Patent (populärvet., debatt m.m.)abstract
- A pressure sensor comprises a pressure-sensitive, flat capsule (1) adapted to be actuated by a pressure which is to be measured, and to be excited to oscillate in mechanical resonance with a resonance frequency dependent on said pressure, as well as to undergo a deformation caused by said pressure, for producing a change in rigidity of the entire capsule (1) and, consequently, an alteration of the resonance frequency thereof. The pressure sensor is characterised in that the capsule (1) is fixed (at 3) with respect to, and adapted to execute said resonance oscillation about, two intersecting unforced nodal lines (10, 11) of the capsule. When the capsule executes its resonance oscillation, it oscillates substantially perpendicular to a geometrical plane common to both nodal lines (10, 11).
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| 20. |
- Svedin, Niklas, et al.
(författare)
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A static turbine flow meter with a micromachined silicon torque sensor
- 2001
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Ingår i: MEMS 2001. - 0780359984 ; , s. 208-211
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Konferensbidrag (refereegranskat)abstract
- A new class of flow sensors is introduced where a static turbine converts the volume flow into a torque. In contrast to conventional turbine meters, the wheel does not rotate and consequently it is not sensitive to bearing friction and wear that a rotating wheel experiences. The sensor performance has been evaluated for different blade lengths and blade angles and a model is given to predict the influence of these parameters. Optimization of the wheel can be done in terms of maximizing the sensitivity/pressure-loss ratio. The most efficient wheel in this analysis has a blade length of 2.7 mm and a blade angle of 30° giving a sensitivity of 4.0 μV/V/(1/min) when measured using a new silicon torque sensor design.
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| 21. |
- Svedin, Niklas, et al.
(författare)
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A static turbine flow meter with a micromachined silicon torque sensor
- 2003
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Ingår i: Journal of microelectromechanical systems. - : Institute of Electrical and Electronics Engineers (IEEE). - 1057-7157 .- 1941-0158. ; 12:6, s. 937-946
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Tidskriftsartikel (refereegranskat)abstract
- A new class of flow sensors is introduced where a static turbine converts the volume flow into a torque. The structure consists of a turbine fixed to a torque sensor, which in turn is connected to the pipe wall giving a perfectly symmetric, bidirectional flowmeter. In contrast to conventional turbine flowmeters, the wheel does not rotate and consequently it is insensitive to bearing friction and wear that conventional, rotating turbines experience. Furthermore, the flow passing the wheel is distributed over the circumference of the wheel and levels out nonuniform flow profiles leading to profile independent volumetric flow measurement. The torque-sensing element is a 300-mum-thick silicon cantilever, 2 mm wide and 16 mm long. The stiffness of the torque sensor, and thereby the sensitivity, is mainly determined by lateral dimensions of specially designed stiffness reduction parts defined by photolithography, thus giving good control of the sensitivity. Two polysilicon strain gauges are placed on each side of the cantilever, measuring the bending moment from the turbine wheel. The torque sensor has been evaluated for different geometries and together with the turbine to evaluate the flow sensing performance. A turbine with a blade length of 2.7 mm and a blade angle of 30degrees has a sensitivity of 4.0 muV/V/(1/min)(2) when measured using the silicon torque sensor. The output signal shows good symmetry between different flow directions.
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| 22. |
- Wuttge, Dirk M., et al.
(författare)
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CXCL16/SR-PSOX is an interferon-gamma-regulated chemokine and scavenger receptor expressed in atherosclerotic lesions
- 2004
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Ingår i: Arteriosclerosis, Thrombosis and Vascular Biology. - : American Heart Association. - 1079-5642 .- 1524-4636. ; 24:4, s. 750-755
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Tidskriftsartikel (refereegranskat)abstract
- OBJECTIVE: Atherosclerosis is an inflammatory disease. Several chemokines are important for monocyte/macrophage and T-cell recruitment to the lesion. CXCL16 is a recently discovered chemokine that is expressed in soluble and transmembrane forms, ligates CXCR6 chemokine receptor, and guides migration of activated Th1 and Tc1 cells. It is identical to scavenger receptor SR-PSOX, which mediates uptake of oxidized low-density lipoprotein. We investigated whether CXCL16 expression is controlled by interferon-gamma (IFN-gamma)-cytokine abundant in atherosclerotic lesions. METHODS AND RESULTS: CXCL16 and CXCR6 expression was identified by polymerase chain reaction and histochemistry in atherosclerotic lesions from humans and apolipoprotein-E-deficient mice. In vitro IFN-gamma induced CXCL16 in human monocytic THP-1 cells and primary human monocytes, which led to increased uptake of oxidized low-density lipoprotein in THP-1 cells, which could be blocked by peptide antibodies against CXCL16. In vivo IFN-gamma induced CXCL16 expression in murine atherosclerotic lesions. CONCLUSIONS: We demonstrate a novel role of IFN-gamma in foam cell formation through upregulation of CXCL16/SR-PSOX. CXCR6 expression in the plaque confirms the presence of cells able to respond to CXCL16. Therefore, this chemokine/scavenger receptor could serve as a molecular link between lipid metabolism and immune activity in the atherosclerotic lesion.
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| 23. |
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| 24. |
- Andersson, Helene, et al.
(författare)
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A valve-less diffuser micropump for microfluidic analytical systems
- 2001
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Ingår i: Sensors and actuators. B, Chemical. - 0925-4005 .- 1873-3077. ; 72:3, s. 259-265
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Tidskriftsartikel (refereegranskat)abstract
- The suitability of valve-less micropumps in biochemistry has been shown. Fluids encountered in various biochemical methods that are problematic for other micropumps have been pumped with good performance. The pump is fabricated as a silicon-glass stack with a new process involving three subsequent deep reactive ion etching steps. Some of the main advantages of the valve-less diffuser pump are the absence of moving parts (excluding the pump diaphragm), the uncomplicated planar design, and high pump performance in terms of pressure head and flow rare. In addition, the micropump is self-priming and insensitive to particles and bubbles present in the pumped media. The results show that the valve-less micropump successfully pumps fluids within the viscosity range of 0.001-0.9 N s/m(2). The micropump is not sensitive to the density, ionic strength, or pH of the pumped media. Effective pumping of solutions containing beads of different sizes was also demonstrated. Living cells were pumped without inducing cell damage and no cell adhesion within the pump chamber was found. No valve-less micropump has previously been reported to pump such a wide variety of fluids.
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