| 1. |
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| 2. |
- Asiatici, Mikhail, et al.
(författare)
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Capacitive inertial sensing at high temperatures of up to 400 degrees C
- 2016
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Ingår i: Sensors and Actuators A-Physical. - : Elsevier. - 0924-4247 .- 1873-3069. ; 238, s. 361-368
-
Tidskriftsartikel (refereegranskat)abstract
- High-temperature-resistant inertial sensors are increasingly requested in a variety of fields such as aerospace, automotive and energy. Capacitive detection is especially suitable for sensing at high temperatures due to its low intrinsic temperature dependence. In this paper, we present high-temperature measurements utilizing a capacitive accelerometer, thereby proving the feasibility of capacitive detection at temperatures of up to 400 degrees C. We describe the observed characteristics as the temperature is increased and propose an explanation of the physical mechanisms causing the temperature dependence of the sensor, which mainly involve the temperature dependence of the Young's modulus and of the viscosity and the pressure of the gas inside the sensor cavity. Therefore a static electromechanical model and a dynamic model that takes into account squeeze film damping were developed.
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| 3. |
- Askfors, Ylva, 1985-, et al.
(författare)
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Learning In Interdisciplinary Networks - For An Efficient Innovation System And An Improved Healthcare
- 2013
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Ingår i: ICERI 2013. - : International Association of Technology, Education and Development, IATED. - 9788461638475 ; , s. 1000-1007
-
Konferensbidrag (refereegranskat)abstract
- Clinical Innovation Fellowships is a program that creates conditions for learning and for innovative thought to take place. It aims to educate innovators and to develop innovations that result in more efficient healthcare production. [1] Multiprofessional 4-person-teams of fellow candidates with competence in engineering, medicine, industrial design and management work together full time for eight months, with the aim to identify clinical needs that can be met by a medical technology innovation (process, product or service) or by an organizational improvement. Early in the program, the team spends two months full time at a clinical department observing the various healthcare activities. Among the clinical needs identified by the fellow candidates three needs will be chosen, validated and approved by the department's management as appropriate starting points for student thesis projects. We describe the phenomenon we have seen when introducing new disciplines as observers and problem solvers in a healthcare context as the improbable dialogue. The improbable dialogue is the unexpected dialogue between professionals and students, or professionals within separate disciplinary boundaries that generally never meet professionally. Such a dialogue may however be the channel in which the curiosity and openness of a novice can reflect on the daily work of a specialist, ultimately resulting in the development of ideas, knowledge exchange and learning. The Clinical Innovation Fellowships program enables this learning to take place and has shown to be a successful catalyst for the improbable dialogue; the unexpected, interdisciplinary, dialogue between healthcare specialists, high qualified fellow candidates with working experience and thesis students from different educational fields. This paper gives a qualitative problematization of the program with respect to the strategy and method of including thesis students to reinforce (almost) any innovation system through interdisciplinary, multiprofessional collaboration, where healthcare and academy learn from each other.
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| 4. |
- Braun, Stefan, et al.
(författare)
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Small footprint knife gate microvalves for large flow control
- 2005
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Ingår i: The 13th International Conference on Solid-State Sensors, Actuators and Microsystems conference (IEEE TRANSDUCERS 2005). - NEW YORK : IEEE conference proceedings. ; , s. 329-332
-
Konferensbidrag (refereegranskat)abstract
- This paper introduces the first area-optimized micromachined knife gate microvalve. In comparison to recent microvalves the pressure-flow performance is increased using out-of-plane actuators and an out-of-plane orifice. Three different actuator-gate designs and their fabrication are described. The valve features integrated therinal silicon/aluminum bimorph actuators where the aluminum layer forins the resistive heater as well as the bimorph material. The characterization of the actuators and of the pressure-flow perfon-nance is presented. The valve allows a flow change of Delta Q=3.4 1/min at 100 kPa on an active chip area of only 2.3 x 3.7 mm(2).
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| 5. |
- Decharat, Adit
(författare)
-
Integration and Packaging Concepts for Infrared Bolometer Arrays
- 2009
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Licentiatavhandling (övrigt vetenskapligt/konstnärligt)abstract
- Infrared (IR) imaging devices based on energy detection has shown a dramatic development in technology along with an impressive price reduction in recent years. However, for a low-end market as in automotive applications, the present cost of IR cameras is still the main obstacle to broadening their usage. Ongoing research has continuously reduced the system cost. Apart from decreasing the cost of infrared optics, there are other key issues to achieve acceptable system costs, including wafer-level vacuum packaging of the detectors, low vacuum level operation, and the use of standard materials in the detector fabrication. This thesis presents concepts for cost reduction of low-end IR cameras. The thesis presents a study of detector performance based on the thermal conductance design of the pixel. A circuit analog is introduced to analyze the basic thermal network effect from the surrounding environment on the conductance from the pixel to the environment. A 3D simulation model of the detector array conductance has been created in order to optimize the performance of the arrays while operated in low vacuum. In the model, Fourier's law of heat transfer is applied to determine the thermal conductance of a composite material pixel. The resulting thermal conductance is then used to predict the performance of the detector array in low vacuum. The investigations of resist as the intermediate bonding material for 3D array integration are also reported in the thesis. A study has been made of the nano-imprint resists series mr-I 9000 using a standard adhesive wafer bonding scheme for thermosetting adhesives. Experiments have been performed to optimize the thickness control and uniformity of the nano-imprint resist layer. The evaluation, including assessment of the bonding surface uniformity and planarizing ability of topographical surfaces, is used to demonstrate the suitability of this resist as sacrificial material for heterogeneous detector array integration. Moreover, the thesis presents research in wafer-level packaging performed by room temperature bonding. Sealing rings, used to create a cavity, are manufactured by electroplating. The cavity sealing is tested by liquid injection and by monitoring the deflection of the lid membrane of the cavities. A value for the membrane deflection is calculated to estimate the pressure inside the cavities.
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| 6. |
- Farjana, Sadia, 1983, et al.
(författare)
-
Dry film photoresist-based microfabrication : A new method to fabricate millimeter-wave waveguide components
- 2021
-
Ingår i: Micromachines. - : MDPI AG. - 2072-666X. ; 12:3
-
Tidskriftsartikel (refereegranskat)abstract
- This paper presents a novel fabrication method based on dry film photoresists to realize waveguides and waveguide-based passive components operating at the millimeter-wave frequency (30–300 GHz). We demonstrate that the proposed fabrication method has a high potential as an alternative to other microfabrication technologies, such as silicon-based and SU8-based micromachining for realizing millimeter-wave waveguide components. Along with the nearly identical transfer of geometrical structures, the dry film photoresist offers other advantages such as fewer processing steps, lower production cost, and shorter prototyping time over the conventional micromachining technologies. To demonstrate the feasibility of the fabrication process, we use SUEX dry film to fabricate a ridge gap waveguide resonator. The resonator is designed to exhibit two resonances at 234.6 and 284 GHz. The measured attenuation at 234 GHz is 0.032 dB/mm and at 283 GHz is 0.033 dB/mm for the fabricated prototype. A comparative study among different existing technologies indicates that the reported method can give a better unloaded Q-value than other conventional processes. The measured unloaded Q-values are in good agreement with the simulated unloaded Q-values. The signal attenuation indicates that SUEX dry film photoresists can be used to fabricate passive devices operating at millimeter-wave frequencies. Moreover, this new fabrication method can offer fast and low-cost prototyping. © 2021 by the authors.
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| 7. |
- Farjana, Sadia, 1983, et al.
(författare)
-
Polymer based 140 GHz Planar Gap Waveguide Array Antenna for Line of Sight (LOS) MIMO Backhaul Links
- 2019
-
Ingår i: IMWS-AMP 2019 - 2019 IEEE MTT-S International Microwave Workshop Series on Advanced Materials and Processes for RF and THz Applications. - : Institute of Electrical and Electronics Engineers Inc.. - 9781728109350 ; July 2918, s. 148-150
-
Konferensbidrag (refereegranskat)abstract
- This paper presents the micromachining based fabrication process of a 140 GHz planar antenna array based on gap waveguide technology to be used in next generation backhauling links. Each antenna element in the bigger 3D-array to be used in LOS MIMO configuration designed to have about 30dBi gain. Each antenna element in the big array consists of several metal layers such as the cavity backed radiation layer and a corporate feed network layer. In this work, we focus on the single antenna array element. Considering some fabrication difficulties as well as focusing on batch fabrication, three different micromachine techniques, SU8 fabrication, PDMS molding and injection molding of polymer OSTEMER has been utilized to fabricate the single antenna device.
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| 8. |
- Farjana, Sadia, 1983, et al.
(författare)
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Realizing a 140 GHz Gap Waveguide–Based Array Antenna by Low-Cost Injection Molding and Micromachining
- 2021
-
Ingår i: Journal of Infrared, Millimeter and Terahertz Waves. - : Springer. - 1866-6892 .- 1866-6906. ; 42:8, s. 893-914
-
Tidskriftsartikel (refereegranskat)abstract
- This paper presents a novel micromachining process to fabricate a 140 GHz planar antenna based on gap waveguide technology to be used in the next-generation backhauling links. The 140 GHz planar array antenna consists of three layers, all of which have been fabricated using polymer-based microfabrication and injection molding. The 140 GHz antenna has the potential to be used as an element in a bigger 3D array in a line-of-sight (LOS) multiple input multiple output (MIMO) configuration to boost the network capacity. In this work, we focus on the fabrication of a single antenna array element based on gap waveguide technology. Depending on the complexity of each antenna layer’s design, three different micromachining techniques, SU8 fabrication, polydimethylsiloxane (PDMS) molding, and injection molding of the polymer (OSTEMER), together with gold (Au) coating, have been utilized to fabricate a single 140 GHz planar array antenna. The input reflection coefficient was measured to be below − 11 dB over a 14% bandwidth from 132 to 152 GHz, and the antenna gain was measured to be 31 dBi at 140 GHz, both of which are in good agreement with the simulations. © 2021, The Author(s).
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| 9. |
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| 10. |
- Haasl, Sjoerd, et al.
(författare)
-
Arrays of monocrystalline silicon micromirrors fabricated using CMOS compatible transfer bonding : IEEE The sixteenth annual international conference on Micro Electro Mechanical Systems
- 2003
-
Ingår i: MEMS-03. - New York : IEEE. - 0780377443 ; , s. 271-274
-
Konferensbidrag (refereegranskat)abstract
- In this paper, we present CMOS compatible fabrication of monocrystalline silicon micromirror arrays using membrane transfer bonding. To fabricate the micromirrors, a thin monocrystalline silicon device layer is transferred from a standard silicon-on-insulator (SOI) wafer to a target wafer (e.g. a CMOS wafer) using low temperature adhesive wafer bonding. In this way, very flat, uniform and low stress micromirror membranes made of monocrystalline silicon can be directly fabricated on top of CMOS circuits. The mirror fabrication does not contain any bond alignment between the wafers; thus, the mirror dimensions and alignment accuracies are only limited by the photolithographic steps. Micromirror arrays with 4x4 pixels and a pitch size of 16mum x 16mum have been fabricated.
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| 11. |
- Haasl, Sjoerd, 1976-
(författare)
-
Assembly of microsystems for optical and fluidic applications
- 2005
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- This thesis addresses assembly issues encountered in optical and fluidic microsystem applications. In optics, the first subject concerns the active alignment of components in optical fibersystems. A solution for reducing the cost of optical component assembly while retaining submicron accuracy is to integrate the alignment mechanism onto the optical substrate. A polymer V-shaped actuator is presented that can carry the weight of the large components - on a micromechanical scale - and that can generate movement with six degrees of freedom. The second subject in optics is the CMOS-compatible fabrication of monocrystalline silicon micromirror arrays that are intended to serve as CMOS-controlled high-quality spatial light modulators in maskless microlithography systems. A wafer-level assembly method is presented that is based on adhesive wafer bonding whereby a monocrystalline layer is transferred onto a substrate wafer in a CMOS-compatible process without needing bond alignment. In fluidics, a hybrid assembly method is introduced that combines two separately micromachined structures to create hotwire anemometers that protrude from a surface with minimum interference with the air flow. The assembled sensor enables one to make accurate time-resolved measurements of the wall shear stress, a quantity that has previously been hard to measure with high time resolution. Also in the field of hotwire anemometers, a method using a hotwire anemometer array is presented for measuring the mass flow, temperature and composition of a gas in a duct. In biochemistry, a bio-analysis chip is presented. Single nucleotide polymorphism scoring is performed using dynamic allele-specific hybridization (DASH). Using monolayers of beads, multiplexing based on single-bead analysis is achieved at heating rates more than 20 times faster than conventional DASH provides. Space and material e±ciency in packaging are the focus of the other two projects in fluidics. The first introduces an assembly based on layering conductive adhesives for the fabrication of miniature polymer electrolyte membrane fuel cells. The fuel cells made with this low-cost approach perform among the best of their type to date. The second project concerns a new cross-flow microvalve concept. Intended as a step towards the mass production of large-flow I/P converters, the silicon footprint area is minimized by an out-of-plane moving gate and in-plane, half-open pneumatic channels.
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| 12. |
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| 13. |
- Haasl, Sjoerd, et al.
(författare)
-
Hybrid mounted micromachined aluminium hot-wire for near-wall turbulence measurements
- 2002
-
Ingår i: FIFTEENTH IEEE INTERNATIONAL CONFERENCE ON MICRO ELECTRO MECHANICAL SYSTEMS. - : IEEE. - 0780371852 ; , s. 336-339
-
Konferensbidrag (refereegranskat)abstract
- We present the first micromachined metal hot-wire anemometer sensor for use in near-wall turbulence measurements. To measure close to the surface without the circuitry interfering with the flow, a novel hybrid assembly of the sensor has been developed. We present the design, fabrication and characteristics of this sensor.
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| 14. |
- Haasl, Sjoerd, et al.
(författare)
-
Hybrid-mounted micromachined aluminum hotwires for wall shear-stress measurements
- 2005
-
Ingår i: Journal of microelectromechanical systems. - : Institute of Electrical and Electronics Engineers (IEEE). - 1057-7157 .- 1941-0158. ; 14:2, s. 254-260
-
Tidskriftsartikel (refereegranskat)abstract
- In this paper, we present a micromachined metal hotwire anemometer sensor for use in wall shear-stress measurements. We describe its design and fabrication. A novel hybrid assembly method has been developed to make it possible to measure close to the surface without contacting leads interfering with the flow. Experimental results illustrate the behavior and characteristics of this sensor.
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| 15. |
- Haasl, Sjoerd, et al.
(författare)
-
Hybrid-mounted micromachined aluminum hotwires for wall shear stress measurements
- 2005
-
Ingår i: Journal of Microelectromechanical Systems. - 1057-7157. ; 14:2, s. 254-260
-
Tidskriftsartikel (refereegranskat)abstract
- In this paper, we present a micromachined metal hotwire anemometer sensor for use in wall shear-stress measurements. We describe its design and fabrication. A novel hybrid assembly method has been developed to make it possible to measure close to the surface without contacting leads interfering with the flow. Experimental results illustrate the behavior and characteristics of this sensor. © 2005 IEEE.
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| 16. |
- Haasl, Sjoerd, et al.
(författare)
-
Out-of-Plane Knife-Gate Microvalves for Controlling Large Gas Flows
- 2006
-
Ingår i: Journal of microelectromechanical systems. - : IEEE Press. - 1057-7157 .- 1941-0158. ; 15:5, s. 1281-1288
-
Tidskriftsartikel (refereegranskat)abstract
- This paper considers design issues for microvalves for large gas flow control. It introduces out-of-plane knife-gate microvalves as a novel design concept and a proportional microvalve concept for pressure control applications. The design of three different actuator-gate configurations and first prototypes are presented. The first valve prototypes feature thermal silicon-aluminum bimorph actuators and the pressure-flow performance per chip area of the demonstrator valve presented is greatly increased using out-of-plane actuation and an out-of-plane orifice. The characterization of the actuators and of the pressure-flow performance is presented. The prototype valve allows for a flow change of Delta Q = 3.4 standard liters per minute (SLPM) at a pressure change of Delta P = 95 kPa (P-in = 196.3 kPa, P-out = 101.3 kPa) on an active chip area of only 2.3 x 3.7 mm(2).
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| 17. |
- Haasl, Sjoerd, et al.
(författare)
-
Physical Sensors : Flow sensors
- 2008
-
Ingår i: Comprehensive Microsystems. - Oxford : Elsevier Science. - 9780444521903
-
Bokkapitel (övrigt vetenskapligt/konstnärligt)
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| 18. |
- Haasl, Sjoerd, et al.
(författare)
-
Robust, large-deflection, in-plane thermal polymer V-shaped actuators
- 2004
-
Ingår i: MEMS 2004. - New York : IEEE. - 078038265X ; , s. 510-513
-
Konferensbidrag (refereegranskat)abstract
- We present the design, fabrication and characteristics of the first in-plane V-shaped polymer actuator. Several different designs are evaluated and compared with each other. The intended application for this actuator is optical component alignment.
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| 19. |
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| 20. |
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| 21. |
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| 22. |
- Hök, Bertil, et al.
(författare)
-
Breath Analyzer for Alcolocks and Screening Devices
- 2010
-
Ingår i: IEEE Sensors Journal. - 1530-437X .- 1558-1748. ; 10, s. 10-15
-
Tidskriftsartikel (refereegranskat)abstract
- Alcolocks and alcohol screening devices are becoming commonplace, and their use is expected to grow rapidly with cost reduction and improved usability. A new breath analyzer prototype is demonstrated, with the prospects of eliminating the mouthpiece, reducing expiration time and volume, improving long-term stability, and reducing life cycle cost. Simultaneous CO2 measurements compensate for the sample dilution and unsaturated expiration. Infrared transmission spectroscopy is used for both the alcohol and CO2 measurement, yet the entire system is contained within a small handheld unit. Experimental results are reported on the device sensitivity, linearity, resolution, and influence from varying measuring distance. The correlation between early and full-time sampling was established in 60 subjects. Basic concept verification was obtained, whereas resolution and selectivity still needs to be improved. Further improvements are expected by system optimization and integration.
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| 23. |
- Jaouen, Frédéric, et al.
(författare)
-
Adhesive copper films for an air-breathing polymer electrolyte fuel cell
- 2005
-
Ingår i: Journal of Power Sources. - : Elsevier BV. - 0378-7753 .- 1873-2755. ; 144:1, s. 113-121
-
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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| 24. |
- Johander, Per, et al.
(författare)
-
Layer Manufacturing as a Generic Tool for Microsystem Integration
- 2007
-
Ingår i: 4M 2007, Third International Conference on Multi-Material Micro Manufacture. - 1904445535 - 9781904445531 - 1420070045 - 9781420070040
-
Konferensbidrag (refereegranskat)abstract
- Nearly every microsystem application requires specific packaging solutions. In this paper we suggest a newapproach to use layer manufacturing as a generic tool for microsystem integration. Three different methods to produce3D electrical interconnects are presented. Ink jet printing is used for the ceramic layer manufacturing process, as well asfor the printing of silver for circuit patterns. The technique is demonstrated for an Inertial Measurement Unit(IMU)platform. A four-sided pyramid was manufactured with layer manufacturing in ceramics and four gyroscopes weremounted on the sides of the pyramid. A demonstrator with three light diodes was also manufactured to demonstrate thepossibility to produce 3D electrical interconnects in the volume of the pyramid.
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| 25. |
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| 26. |
- Khan, Mohammed Faheem, et al.
(författare)
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Methods for characterization of wafer-level encapsulation applied on Si to LTCC Anodic bonding
- 2010
-
Ingår i: Journal of Micromechanics and Microengineering. - : IOP Publishing. - 0960-1317 .- 1361-6439. ; 20:6
-
Tidskriftsartikel (refereegranskat)abstract
- This paper presents initial results on generic characterization methods for wafer-level encapsulation. The methods, developed specifically to evaluate anodic bonding of low-temperature cofired ceramics (LTCC) to Si, are generally applicable to wafer-level encapsulation. Different microelectromechanical system (MEMS) structures positioned over the whole wafer provide local information about the bond quality. The structures include (i) resonating cantilevers as pressure sensors for bond hermeticity, (ii) resonating bridges as stress sensors for measuring the stress induced by the bonding and (iii) frames/mesas for pull tests. These MEMS structures have been designed, fabricated and characterized indicating that local information can easily be obtained. Buried electrodes to enable localized bonding have been implemented and their effectiveness is indicated from first results of the novel Si to LTCC anodic bonding.
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| 27. |
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| 28. |
- Kuch, B., et al.
(författare)
-
Preliminary report : Embedded platform for inertial based underwater navigation
- 2011
-
Ingår i: Proc. Ninth Workshop Intelligent Solutions in Embedded Systems (WISES). - 9783000334016 ; , s. 101-108
-
Konferensbidrag (refereegranskat)abstract
- A diver uses typically a compass, a depth gauge and a timer for underwater navigation. Especially when it comes to advanced diving in caves or wrecks, navigation and knowledge about the current position is extremely important, otherwise the diver might not find his way back to the surface and drown as soon as the breathing gas supply is finished. Other approaches are based on ultrasound transmitters that allow simple navigation tasks, however they are useless for applications like cave, wreck or long distance diving. The current paper describes a navigation platform for divers which is based on a handset with a depth sensor and a display, an inertial measurement unit incorporation gyroscopes, accelerometers and magentometers and an interface to attach different kinds of flow sensors for velocity measurement. A first prototype was developed. Additionally a buoy with an integrated GSM/GPS transmitter and a reference system for laboratory measurements can be attached. The prototype was validated in a pool and tests with the GPS reference system were carried out in the open sea.
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| 29. |
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| 30. |
- Löfdahl, Lennart, 1948, et al.
(författare)
-
Characteristics of a hot-wire microsensor for time-dependent wall shear stress measurements
- 2003
-
Ingår i: Experiments in Fluids. - : Springer Science and Business Media LLC. - 0723-4864 .- 1432-1114. ; 35:3, s. 240-251
-
Tidskriftsartikel (refereegranskat)abstract
- Hot-wire microsensors for the purpose of measuring the instantaneous velocity gradient close to a wall were designed and their characteristics were evaluated. The sensors were made using MEMS (microelectromechanical systems) technology, which permits the fabrication of various microgeometrical configurations with high precision and good repeatability. The design is based on estimates of the heat rates from the sensor wire to the air, through the supports, and to the wall. Several hot-wire configurations were fabricated with wires positioned in the range 50-250 mum from the wall. Requirements for the design and details of the fabrication methodology are outlined. The hot-wire microsensors were calibrated and tested in a flat-plate boundary layer with and without pressure gradients and were found to have good steady-state characteristics. In addition, the developed sensors were used for preliminary studies of transitional phenomena and turbulence, and the sensors were found to have a good time-dependent response as well.
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| 31. |
- Löfgren, Linus, et al.
(författare)
-
Low-power humidity sensor
- 2008
-
Ingår i: Proceedings of Eurosensors. ; , s. 231-234
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Konferensbidrag (refereegranskat)
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| 32. |
- Löfgren, Linus, et al.
(författare)
-
Low-power humidity sensor for RFID applications
- 2008
-
Ingår i: 4M2008 Conference, Cardiff, UK.
-
Konferensbidrag (refereegranskat)abstract
- Wireless sensors incorporated in RFID systems are important in several industrial, consumer and logisticsapplications. By extending RFID tags to sensing applications, the products become smarter. Application areas forthese smart tags include; health care (verification of the environmental conditions during transport or in storage of e.g.diapers, bandages, etc.), food monitoring (food quality during transport, storage and sales) and construction industry(e.g. building material).In this paper, a small, very low power and low cost humidity sensor tailor made for passive RFID applications ispresented. The sensor consists of a glass chip substrate with a sub-micron interdigitated gold electrode structurecovered with a humidity sensitive polyimide layer. The humidity absorbed by the sensing layer is measuredcapacitively. Finite element modeling and analytic calculations were used to determine the design of the interdigitatedelectrodes and the optimal thickness of the polyimide layer. A read-out electronics circuit was designed and used toevaluate the sensor. Sensors were fabricated and calibrations have been made to verify their function. The sensorresponse was close to linear from below 20 to above 90 %RH and its response time was proven to be at least as shortas that of the climate chamber, namely 0.1 %RH/s. The concept can easily be adapted to measure a range of otherparameters such as temperature or the presence of certain substances.
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| 33. |
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| 34. |
- Najmzadeh, Mohammad, 1981, et al.
(författare)
-
A silicon straight tube fluid density sensor
- 2007
-
Ingår i: journal of micromechanics and microengineering. - : IOP Publishing. ; 17:8
-
Tidskriftsartikel (refereegranskat)abstract
- In this paper, a new and simple silicon straight tube is tested as a fluid density sensor. The tube structure has a hexagonal cross section. The fabrication process consists of anisotropic silicon etching and silicon fusion bonding. A tube structure with a length of 2.65 cm was tested. The sample volume is 9.3 μL. The first three modes of vibrations were investigated with a laser Doppler vibrometer for air and five liquid mixtures. The fluid density sensitivity of each mode was measured and the average was −256 ± 6 ppm (kg m−3)−1 around the density of water. The density of an unknown fluid can be continuously monitored using this sensor by measuring the resonance frequency of one of the vibration modes and extracting the density from the calibration curves.
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| 35. |
- Najmzadeh, Mohammad, 1981, et al.
(författare)
-
A Straight Silicon Tube As A Microfluidic Density Sensor
- 2007
-
Ingår i: Proceedings of the 11th inernational conference on miniaturized systems for chemistry and life sciences (MicroTAS). - 9780979806407 ; 1, s. 536-538, s. 536-538
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Konferensbidrag (refereegranskat)
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| 36. |
- Najmzadeh, M., et al.
(författare)
-
Silicon Straight Tube Fluid Density Sensor
- 2007
-
Ingår i: Proceedings of IEEE Sensors. - 9781424412617 ; , s. 1185-1188
-
Konferensbidrag (refereegranskat)abstract
- In this paper, a micromachined silicon straight tube is tested as a fluid density sensor. In comparison with other density measurement techniques, the use of micromachined tubes require small sample volumes and allows continuous monitoring of the fluid density in microfluidic systems. Different vibration modes of the sensor were detected and calibrated using a laser Doppler vibrometer (LDV). Linearity, simplicity, the straightforward fabrication and evaluation, the low flow restriction and reduced risk of trapping gas in the sensor due the absence of corners are the design’s main advantages. The ability of the sensor to measure density of multiphase fluids and provide accurate results independent of other fluid parameters, allows it to be used in varying fields such as the biomedical, pharmaceutical and petrochemical industries.
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| 37. |
- Najmzadeh, Mohammad, 1981, et al.
(författare)
-
Silicon straight tube fluid density sensor
- 2007
-
Ingår i: proceedings of the 6th IEEE conference on sensors, Oct. 28-31, 2007, Atlanta. ; 1, s. 1185-1188
-
Konferensbidrag (refereegranskat)
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| 38. |
- Niklaus, Frank, et al.
(författare)
-
Arrays of monocrystalline silicon micromirrors fabricated using CMOS compatible transfer bonding
- 2003
-
Ingår i: Journal of microelectromechanical systems. - : Institute of Electrical and Electronics Engineers (IEEE). - 1057-7157 .- 1941-0158. ; 12:4, s. 465-469
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Tidskriftsartikel (refereegranskat)abstract
- In this paper, we present CMOS compatible fabrication of monocrystalline silicon micromirror arrays using membrane transfer bonding. To fabricate the micromirrors, a thin monocrystalline silicon device layer is transferred from a standard silicon-on-insulator (SOI) wafer to a target wafer (e.g., a CMOS wafer) using low-temperature adhesive wafer bonding. In this way, very flat, uniform and low-stress micromirror membranes made of monocrystalline silicon can be directly fabricated on top of CMOS circuits. The mirror fabrication does not contain any bond alignment between the wafers, thus, the mirror dimensions and alignment accuracies are only limited by the photolithographic steps. Micromirror arrays with 4 x 4 pixels and a pitch size of 16 mum x 16 mum have been fabricated. The monocrystalline silicon micromirrors are 0.34 mum thick and have feature sizes as small as 0.6 mum. The distance between the addressing electrodes and the mirror membranes is 0.8 mum. Torsional micromirror arrays are used as spatial light modulators, and have potential applications in projection display systems, pattern generators for maskless lithography systems, optical spectroscopy, and optical communication systems. In principle, the membrane transfer bonding technique can be applied for integration of CMOS circuits with any type of transducer that consists of membranes and that benefits from the use of high temperature annealed or monocrystalline materials. These types of devices include thermal infrared detectors, RF-MEMS,IS devices, tuneable vertical cavity surface emitting lasers (VCSEL) and other optical transducers.
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| 39. |
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| 40. |
- Rahiminejad, Sofia, 1987, et al.
(författare)
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100 GHz SOI gap waveguides
- 2013
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Ingår i: 2013 Transducers and Eurosensors XXVII. - 9781467359818 ; , s. 510-513
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Konferensbidrag (refereegranskat)abstract
- Two gap waveguide technologies, groove and ridge, are presented here for F-band applications. Three different groove gap waveguide devices and four different ridge gap waveguide devices have been fabricated. All of them were micromachined to achieve the feature size required for the frequency band and fabricated in a single process using SOI wafers. The two types provide a more robust coupling to standard waveguides and high frequency probes. Measurements for most of the devices are shown in this paper, showing robust measurements and good agreement with simulations. More measurements need to be done but the initial ones show the promise both in the manufacturing technique and the coupling.
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| 41. |
- Rahiminejad, Sofia, 1987, et al.
(författare)
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AMC pin waveguide flange for screw redundant millimeter and submillimeter measurements
- 2016
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Ingår i: 87th ARFTG Microwave Measurement Conference: Measurements for Emerging Communications Technologies, ARFTG 2016. - 9781509013081 ; , s. 7501946-
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Konferensbidrag (refereegranskat)abstract
- Measurements with waveguide flanges at frequencies above 100GHz have a considerable issue with leakage due to problems with achieving good electrical contact between the opposite flanges. The higher the frequency, the higher is the requirement for full contact. However, by using an artificial magnetic conducting (AMC) flange on one side of the interface, full electric contact is not needed between the two joining flanges. The AMC is realized as a pin-surface, and the leakage is stopped by a parallel-plate stopband like in gap waveguides. This paper describes how these AMC pin waveguide flanges can be used for screw redundant measurements.
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| 42. |
- Rahiminejad, Sofia, 1987, et al.
(författare)
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Demonstration of a micromachined planar distribution network in gap waveguide technology for a linear slot array antenna at 100 GHz
- 2016
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Ingår i: Journal of Micromechanics and Microengineering. - : IOP Publishing. - 1361-6439 .- 0960-1317. ; 26:7, s. Art. no. 074001-
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Tidskriftsartikel (refereegranskat)abstract
- The need for high frequency antennas is rapidly increasing with the development of new wireless rate communication technology. Planar antennas have an attractive form factor, but they require a distribution network. Microstrip technology is most commonly used at low frequency but suffers from large dielectric and ohmic losses at higher frequencies and particularly above 100 GHz. Substrate-integrated waveguides also suffer from dielectric losses. In addition, standard rectangular waveguide interfaces are inconvenient due to the four flange screws that must be tightly fastened to the antenna to avoid leakage. The current paper presents a planar slot array antenna that does not suffer from any of these problems. The distribution network is realized by micromachining using low-loss gap waveguide technology, and it can be connected to a standard rectangular waveguide flange without using any screws or additional packaging. To realize the antenna at these frequencies, it was fabricated with micromachining, which offers the required high precision, and a low-cost fabrication method. The antenna was micromachined with DRIE in two parts, one silicon-on-insulator plate and one Si plate, which were both covered with Au to achieve conductivity. The input reflection coefficient was measured to be below 10 dB over a 15.5% bandwidth, and the antenna gain was measured to be 10.4 dBi, both of which are in agreement with simulations.
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| 43. |
- Rahiminejad, Sofia, 1987, et al.
(författare)
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Design of micromachined ridge gap waveguides for millimeter-wave applications
- 2011
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Ingår i: Procedia Eng.. - : Elsevier BV. ; 25, s. 519-522
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Konferensbidrag (refereegranskat)abstract
- The ridge gap waveguide is a new transmission line for millimeter-wave applications. Traditionally, rectangular waveguides are used for those applications due to their low loss. However their fabrication requires precision machining, very good electrical contact and alignment between two joining mechanical parts. Ridge gap waveguides can obtain similar performance without requiring conductive sidewalls and this provides more freedom during the fabrication and assembly process as the structure is no longer sensitive to small gaps between the side walls and the upper lid. The ridge gap waveguide has already been validated for 10-20 GHz using conventional fabrication methods. The ridge gap waveguide prototypes presented in this paper are designed to work in the frequency region between 210 and 340 GHz, and fabricated using MEMS technology. MEMS technology provides fabrication precision of the structures and thus opens the path for high-frequency components.
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| 44. |
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| 45. |
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| 46. |
- Rahiminejad, Sofia, 1987, et al.
(författare)
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MICORMACHINED MULTILAYER SU8 DOUBLE-SIDED PIN-FLANGE ADAPTER FOR 220-325 GHZ
- 2014
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Ingår i: 25th Micromechanics and Microsystems Europe Workshop, MME 2014, Istanbul, Turkey, August 31 - September 3, 2014.
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Konferensbidrag (refereegranskat)abstract
- We present the first double-sidedpin-flange adapter for 220 ? 325 GHz solely madeout of gold covered multilayered SU8. The processis based on exposing layers with different patternsrealizing openings through both layers and pinstructures in only one of the layers. Each processgives two layers which are then bonded back toback resulting in a four layer device. SU8 has thebenefit of being cheap and robust compared to Siand is useful for applications where the device willbe handled by hand and could be exposed to unevenforces. The multilayer SU8 double-sided pin-flangeadapter was successfully fabricated. Measurementsand evaluations will be presented at the conference.
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| 47. |
- Rahiminejad, Sofia, 1987, et al.
(författare)
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Micromachined contactless pin-flange adapter for robust high-frequency measurements
- 2014
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Ingår i: Journal of Micromechanics and Microengineering. - : IOP Publishing. - 1361-6439 .- 0960-1317. ; 24:8, s. Art. no. 084004-
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Tidskriftsartikel (refereegranskat)abstract
- We present the first micromachined double-sided contactless WR03 pin-flange adapter for 220-325 GHz based on gap waveguide technology. The pin-flange adapter is used to avoid leakage at the interface of two waveguides even when a gap between them is present and can be fitted onto any standard WR03 waveguide flange. Tolerance measurements were performed with gaps ranging from 30-100 mu m. The performance of the micromachined pin flange has been compared to a milled pin flange, a choke flange and to standard waveguide connections. The micromachined pin flange is shown to have better performance than the standard connection and similar performance to the milled pin flange and choke flange. The benefits of micromachining over milling are the possibility to mass produce pin flanges and the better accuracy in the 2D design. Measurements were performed with and without screws fixing the flanges. The flanges have also been applied to measure two devices, a straight rectangular waveguide of 1.01 inch and a ridge gap resonator. In all cases, the micromachined pin flange performed flawlessly while the standard flange experienced significant losses at already small gaps.
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| 48. |
- Rahiminejad, Sofia, 1987, et al.
(författare)
-
Micromachined gap waveguide devices for above 100 GHz
- 2014
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Ingår i: Swedish Microwave Days March 11-12, 2014.
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Konferensbidrag (refereegranskat)abstract
- Gap waveguide technology is a fundamentally new highfrequencywaveguide technology [1]. It does not need anyelectrical contact between the split blocks which gives it anadvantage, compared to the rectangular waveguide.Rectangular waveguides are often fabricated by milling.However there are issues with milling when constructingwaveguides above 100 GHz. MEMS technology can offerhigh-precision fabrication and thus enables the path for newtypes of high-frequency components. An overview of themicromachined gap waveguide devices that has beenfabricated for above 100 GHz are presented here.
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| 49. |
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| 50. |
- Rahiminejad, Sofia, 1987, et al.
(författare)
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Micromachined gap waveguides for 100 GHz applications
- 2013
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Ingår i: 2013 7th European Conference on Antennas and Propagation, EuCAP 2013. - : EurAAP. - 9788890701832 ; , s. 1935-1938
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Konferensbidrag (refereegranskat)abstract
- The present paper demonstrates groove gap waveguides at around 100 GHz, fabricated on Gold-plated micromachined silicon. Three different groove gap waveguides have been manufactured and measured: a resonator for determining Q-factor and thereby attenuation, a straight waveguide, and a waveguide with two 90 degree bends.
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