Pub Date : 2007-01-01DOI: 10.1109/MEMSYS.2007.4433127
Chin-Pang-Billy Siu, H. Zeng, M. Chiao
This paper presents the design, fabrication and characterization of a magnetically actuated scanning microlens for miniature confocal near infrared (NIR) Raman spectroscopy. One of the potential applications could be on non-invasive skin cancer diagnosis. The microlens is comprised of a 20 mum thick ferromagnetic nickel platform integrated with a PDMS plano-convex lens with a diameter of 1.25 mm and an effective focal length of 2.0 mm. This work demonstrates a microlens with a scanning angle of plusmn24deg driven by an external AC magnetic field orientated at an angle of 30deg from the horizontal rotation axis. A coplanar 152 mum scanning range is demonstrated by a 22.2times10-3 Tesla external magnetic field at 197 Hz.
{"title":"Magnetically actuated scanning microlens for NIR Raman spectroscopy","authors":"Chin-Pang-Billy Siu, H. Zeng, M. Chiao","doi":"10.1109/MEMSYS.2007.4433127","DOIUrl":"https://doi.org/10.1109/MEMSYS.2007.4433127","url":null,"abstract":"This paper presents the design, fabrication and characterization of a magnetically actuated scanning microlens for miniature confocal near infrared (NIR) Raman spectroscopy. One of the potential applications could be on non-invasive skin cancer diagnosis. The microlens is comprised of a 20 mum thick ferromagnetic nickel platform integrated with a PDMS plano-convex lens with a diameter of 1.25 mm and an effective focal length of 2.0 mm. This work demonstrates a microlens with a scanning angle of plusmn24deg driven by an external AC magnetic field orientated at an angle of 30deg from the horizontal rotation axis. A coplanar 152 mum scanning range is demonstrated by a 22.2times10-3 Tesla external magnetic field at 197 Hz.","PeriodicalId":6388,"journal":{"name":"2007 IEEE 20th International Conference on Micro Electro Mechanical Systems (MEMS)","volume":"39 1","pages":"735-738"},"PeriodicalIF":0.0,"publicationDate":"2007-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"87097302","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2007-01-01DOI: 10.1109/MEMSYS.2007.4433078
C. K. Eun, T. Fung, B. Mitra, Y. Gianchandani
This paper explores a 3-electrode micromachined Geiger counter utilizing a high impedance (floating) electrode to control discharge energy, and its impact on sensitivity and response time. Permanent magnets in a sandwich configuration are used to enhance RF transmission from micro-discharges. Initially, weak (field-emission) leakage current charges the floating electrode capacitor (CPap1.1 pF) to a high voltage through the charging gap (between floating electrode and anode). When beta radiation initiates a micro-discharge in the sensing gap (between floating electrode and cathode), CP dissipates through the low impedance path, lowering the voltage and quickly quenching the discharge. Permanent magnets, positioned perpendicular to the discharge path, increase the efficiency of electron-ion collisions and enhance the consequent RF transmission. Experiments conducted in a neon/air ambient with 90Sr (0.1 muCi) showed a 10times-100times SNR improvement for the 3-electrode design over a similar 2-electrode design that does not utilize the floating electrode. Results also showed a significant increase in high frequency components in the presence of a magnetic field.
{"title":"A magnetically enhanced 3-electrode wireless micro-geiger counter","authors":"C. K. Eun, T. Fung, B. Mitra, Y. Gianchandani","doi":"10.1109/MEMSYS.2007.4433078","DOIUrl":"https://doi.org/10.1109/MEMSYS.2007.4433078","url":null,"abstract":"This paper explores a 3-electrode micromachined Geiger counter utilizing a high impedance (floating) electrode to control discharge energy, and its impact on sensitivity and response time. Permanent magnets in a sandwich configuration are used to enhance RF transmission from micro-discharges. Initially, weak (field-emission) leakage current charges the floating electrode capacitor (CPap1.1 pF) to a high voltage through the charging gap (between floating electrode and anode). When beta radiation initiates a micro-discharge in the sensing gap (between floating electrode and cathode), CP dissipates through the low impedance path, lowering the voltage and quickly quenching the discharge. Permanent magnets, positioned perpendicular to the discharge path, increase the efficiency of electron-ion collisions and enhance the consequent RF transmission. Experiments conducted in a neon/air ambient with 90Sr (0.1 muCi) showed a 10times-100times SNR improvement for the 3-electrode design over a similar 2-electrode design that does not utilize the floating electrode. Results also showed a significant increase in high frequency components in the presence of a magnetic field.","PeriodicalId":6388,"journal":{"name":"2007 IEEE 20th International Conference on Micro Electro Mechanical Systems (MEMS)","volume":"6 1","pages":"599-602"},"PeriodicalIF":0.0,"publicationDate":"2007-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"90936140","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2007-01-01DOI: 10.1109/MEMSYS.2007.4433150
C. Iliescu, Bangtao Chen, J. Miao
This paper addresses the main issues related to wet micromachining of one of the mostly used BioMEMS materials - glass - and proposes two optimized solutions for deep wet etching. As a result, 500 mum-thick Pyrex glass wafer was etched using an etching mask consisting of low stress amorphous silicon (a: Si) and photoresist. Moreover we report the successful through etching of 1 mm Pyrex glass wafer using a combination of low stress a: Si/SiC/photoresist mask.
{"title":"Deep wet etching-through 1mm pyrex glass wafer for microfluidic applications","authors":"C. Iliescu, Bangtao Chen, J. Miao","doi":"10.1109/MEMSYS.2007.4433150","DOIUrl":"https://doi.org/10.1109/MEMSYS.2007.4433150","url":null,"abstract":"This paper addresses the main issues related to wet micromachining of one of the mostly used BioMEMS materials - glass - and proposes two optimized solutions for deep wet etching. As a result, 500 mum-thick Pyrex glass wafer was etched using an etching mask consisting of low stress amorphous silicon (a: Si) and photoresist. Moreover we report the successful through etching of 1 mm Pyrex glass wafer using a combination of low stress a: Si/SiC/photoresist mask.","PeriodicalId":6388,"journal":{"name":"2007 IEEE 20th International Conference on Micro Electro Mechanical Systems (MEMS)","volume":"98 3 1","pages":"393-396"},"PeriodicalIF":0.0,"publicationDate":"2007-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"72709419","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2007-01-01DOI: 10.1109/MEMSYS.2007.4433074
T. Murakami, T. Sugie, T. Kon, R. Yokokawa
This paper reports a nanotransport system with the directional movement control. The system consists of motor proteins, dynein and kinesin, and their tracks, microtubules. Dynein molecules are specifically immobilized on a microchannel glass surface and fluorescently labeled microtubules were transported by dynein motion. Moving directions of gliding microtubules were controlled by a pressure-driven flow through the microchannel, and their polarities were oriented in the designated direction. We have also examined their polarities by the unidirectional transport of kinesin-coated microspheres. Orientation ratios of microtubules were evaluated as 90.9% and 78.8% by moving microtubules and microspheres, respectively. Integrating dynein and kinesin provides a possibility to compose a two-dimensional nanotransport system.
{"title":"Unidirectional motion of microtubules and microspheres by Dynein motor protein","authors":"T. Murakami, T. Sugie, T. Kon, R. Yokokawa","doi":"10.1109/MEMSYS.2007.4433074","DOIUrl":"https://doi.org/10.1109/MEMSYS.2007.4433074","url":null,"abstract":"This paper reports a nanotransport system with the directional movement control. The system consists of motor proteins, dynein and kinesin, and their tracks, microtubules. Dynein molecules are specifically immobilized on a microchannel glass surface and fluorescently labeled microtubules were transported by dynein motion. Moving directions of gliding microtubules were controlled by a pressure-driven flow through the microchannel, and their polarities were oriented in the designated direction. We have also examined their polarities by the unidirectional transport of kinesin-coated microspheres. Orientation ratios of microtubules were evaluated as 90.9% and 78.8% by moving microtubules and microspheres, respectively. Integrating dynein and kinesin provides a possibility to compose a two-dimensional nanotransport system.","PeriodicalId":6388,"journal":{"name":"2007 IEEE 20th International Conference on Micro Electro Mechanical Systems (MEMS)","volume":"30 1","pages":"473-476"},"PeriodicalIF":0.0,"publicationDate":"2007-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"77222775","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2007-01-01DOI: 10.1109/MEMSYS.2007.4433153
Yuejun Zhao, U. Yi, S. Cho
This paper describes highly efficient in-droplet particle concentrations/separations (over 92% efficiency), where target particles are concentrated/separated within a droplet by traveling wave dielectrophoresis (twDEP) and a subsequent EWOD (electrowetting-on-dielectric) actuation physically splits target-rich regions into individual droplets. This in-droplet method will provide a new functionality of separation/concentration for digital (droplet-based) microfluidics [1], thereby possibly eliminating the necessity of adopting the conventional continuous-flow-based separation methods.
{"title":"Highly efficient in-droplet particle concentration and separation by twDEP and EWOD for digital microfluidics","authors":"Yuejun Zhao, U. Yi, S. Cho","doi":"10.1109/MEMSYS.2007.4433153","DOIUrl":"https://doi.org/10.1109/MEMSYS.2007.4433153","url":null,"abstract":"This paper describes highly efficient in-droplet particle concentrations/separations (over 92% efficiency), where target particles are concentrated/separated within a droplet by traveling wave dielectrophoresis (twDEP) and a subsequent EWOD (electrowetting-on-dielectric) actuation physically splits target-rich regions into individual droplets. This in-droplet method will provide a new functionality of separation/concentration for digital (droplet-based) microfluidics [1], thereby possibly eliminating the necessity of adopting the conventional continuous-flow-based separation methods.","PeriodicalId":6388,"journal":{"name":"2007 IEEE 20th International Conference on Micro Electro Mechanical Systems (MEMS)","volume":"59 1","pages":"537-540"},"PeriodicalIF":0.0,"publicationDate":"2007-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"76819659","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2007-01-01DOI: 10.1109/MEMSYS.2007.4433135
J. Tong, M. Priebe, Yu Sun
This paper presents the design, fabrication, and testing results of silicon cantilevers with carbon nanotubes (CNTs) as active strain sensing elements. A batch microfabrication process was developed for device construction and packaging. Multi-walled carbon nanotubes (MWNTs) were dielectrophoretically assembled between electrodes. Based on the characterization results of 12 devices, the CNT-based cantilevers demonstrated a linear relationship between resistance changes and externally applied strain. The gauge factor ranged from 78.84 to 134.40 for four different microelectrode configurations.
{"title":"Carbon nanotube-based strain sensing cantilevers","authors":"J. Tong, M. Priebe, Yu Sun","doi":"10.1109/MEMSYS.2007.4433135","DOIUrl":"https://doi.org/10.1109/MEMSYS.2007.4433135","url":null,"abstract":"This paper presents the design, fabrication, and testing results of silicon cantilevers with carbon nanotubes (CNTs) as active strain sensing elements. A batch microfabrication process was developed for device construction and packaging. Multi-walled carbon nanotubes (MWNTs) were dielectrophoretically assembled between electrodes. Based on the characterization results of 12 devices, the CNT-based cantilevers demonstrated a linear relationship between resistance changes and externally applied strain. The gauge factor ranged from 78.84 to 134.40 for four different microelectrode configurations.","PeriodicalId":6388,"journal":{"name":"2007 IEEE 20th International Conference on Micro Electro Mechanical Systems (MEMS)","volume":"33 1","pages":"843-846"},"PeriodicalIF":0.0,"publicationDate":"2007-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"76166025","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2007-01-01DOI: 10.1109/MEMSYS.2007.4433137
D. Takagi, Y. Suzuki, N. Kasagi
In this report, we propose Si microcavities coated with parylene-pyrolyzed carbon as a selective emitter for high-efficiency thermophotovoltaic (TPV) power generation system. In order to obtain carbon films with uniform thickness on three-dimensional Si structures, we adopt CxFy deposition on the top of the parylene film before the pyrolysis. The carbon yield doubles with the CxFy deposition. We also demonstrate that the Si microcavities coated with carbon thus fabricated exhibit an emittance peak near the wavelength of 2.6 mum, which corresponds to the characteristic electromagnetic mode of the cavity.
{"title":"Pyrolyzed parylene structure as selective emittter for high-efficiency thermophotovoltaic power generation","authors":"D. Takagi, Y. Suzuki, N. Kasagi","doi":"10.1109/MEMSYS.2007.4433137","DOIUrl":"https://doi.org/10.1109/MEMSYS.2007.4433137","url":null,"abstract":"In this report, we propose Si microcavities coated with parylene-pyrolyzed carbon as a selective emitter for high-efficiency thermophotovoltaic (TPV) power generation system. In order to obtain carbon films with uniform thickness on three-dimensional Si structures, we adopt CxFy deposition on the top of the parylene film before the pyrolysis. The carbon yield doubles with the CxFy deposition. We also demonstrate that the Si microcavities coated with carbon thus fabricated exhibit an emittance peak near the wavelength of 2.6 mum, which corresponds to the characteristic electromagnetic mode of the cavity.","PeriodicalId":6388,"journal":{"name":"2007 IEEE 20th International Conference on Micro Electro Mechanical Systems (MEMS)","volume":"282 1","pages":"883-886"},"PeriodicalIF":0.0,"publicationDate":"2007-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"79826514","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2007-01-01DOI: 10.1109/MEMSYS.2007.4433112
H. Kitagawa, Wei-heong Tan, S. Takeuchi
This work is motivated by the need for accurate positioning of both adherent and non-adherent cells into arrays that can be integrated with microfluidic channels in high-throughput screening (HTS) for drug discovery. We describe a microfluidic device that allows rapid production of uniform micro hydrogel capsules that can contain cells. Up to 1times104 hydrogel capsules can be simply formed and arrayed simultaneously using microchambers in a 10 mm long microchannel. In this work, alginate was used as the hydrogel capsules that can be dissolved and removed with EDTA; thus samples confined in the capsules are collectable after observation in the array. We demonstrated the microencapsulation of E. coli into alginate capsules, and dissolved the capsules with EDTA successfully.
{"title":"Mass production of uniform alginate capsules for micro cell encapslation using micro chamber array","authors":"H. Kitagawa, Wei-heong Tan, S. Takeuchi","doi":"10.1109/MEMSYS.2007.4433112","DOIUrl":"https://doi.org/10.1109/MEMSYS.2007.4433112","url":null,"abstract":"This work is motivated by the need for accurate positioning of both adherent and non-adherent cells into arrays that can be integrated with microfluidic channels in high-throughput screening (HTS) for drug discovery. We describe a microfluidic device that allows rapid production of uniform micro hydrogel capsules that can contain cells. Up to 1times104 hydrogel capsules can be simply formed and arrayed simultaneously using microchambers in a 10 mm long microchannel. In this work, alginate was used as the hydrogel capsules that can be dissolved and removed with EDTA; thus samples confined in the capsules are collectable after observation in the array. We demonstrated the microencapsulation of E. coli into alginate capsules, and dissolved the capsules with EDTA successfully.","PeriodicalId":6388,"journal":{"name":"2007 IEEE 20th International Conference on Micro Electro Mechanical Systems (MEMS)","volume":"28 1","pages":"493-496"},"PeriodicalIF":0.0,"publicationDate":"2007-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"81514059","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2007-01-01DOI: 10.1109/MEMSYS.2007.4433093
P. Stephanou, A. Pisano
This work introduces a new class of low motional resistance piezoelectric aluminum nitride (AlN) MEMS ring resonators that operate in GHz contour modes of vibration. The resonators are based on an annular thin film AlN structural layer sandwiched between two or more pairs of concentric transduction electrodes whose design effectively uncouples the resonant frequency of the device from its transduction area (and consequently its motional resistance) at the layout level. The devices under test exhibit lithographically-defined fundamental series resonant frequencies from 1.03 to 1.60 GHz, motional resistances from 57 to 130 Omega, a resonator figure of merit (FOM = kt 2Q) of 6.4 to 7.4, and no coherent spurious responses from DC to 5 GHz.
{"title":"GHZ higher order contour mode ALN annular resonators","authors":"P. Stephanou, A. Pisano","doi":"10.1109/MEMSYS.2007.4433093","DOIUrl":"https://doi.org/10.1109/MEMSYS.2007.4433093","url":null,"abstract":"This work introduces a new class of low motional resistance piezoelectric aluminum nitride (AlN) MEMS ring resonators that operate in GHz contour modes of vibration. The resonators are based on an annular thin film AlN structural layer sandwiched between two or more pairs of concentric transduction electrodes whose design effectively uncouples the resonant frequency of the device from its transduction area (and consequently its motional resistance) at the layout level. The devices under test exhibit lithographically-defined fundamental series resonant frequencies from 1.03 to 1.60 GHz, motional resistances from 57 to 130 Omega, a resonator figure of merit (FOM = kt 2Q) of 6.4 to 7.4, and no coherent spurious responses from DC to 5 GHz.","PeriodicalId":6388,"journal":{"name":"2007 IEEE 20th International Conference on Micro Electro Mechanical Systems (MEMS)","volume":"21 1","pages":"787-790"},"PeriodicalIF":0.0,"publicationDate":"2007-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"88722268","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2007-01-01DOI: 10.1109/MEMSYS.2007.4433060
T. Galchev, W. Welch, K. Najafi
This paper explores the use of dielectric barrier discharge (DBD) surface activated low-temperature wafer bonding in MEMS device fabrication. Characterization of the DBD surface treatment process is included as well as analysis of the optimal bonding conditions. A new high aspect-ratio MEMS technology based on bonding two silicon wafers with an intermediate silicon dioxide layer at 400degC is presented. This silicon-on-silicon (SOS) process requires three masks and provides several advantages compared with silicon-on-glass (SOG) and silicon-on- insulator (SOI) processes, including better dimensional and etch profile control of narrow and slender MEMS structures. This is demonstrated by fabricating a 5 mum wide 30 mm long beam. Additionally, by patterning the intermediate SiO2 insulation layer before bonding, footing is reduced without any extra processing, as compared to both SOG and SOI. All SOS process steps are CMOS compatible.
{"title":"Low-temperature MEMS process using plasma activated Silicon-On-Silicon (SOS) bonding","authors":"T. Galchev, W. Welch, K. Najafi","doi":"10.1109/MEMSYS.2007.4433060","DOIUrl":"https://doi.org/10.1109/MEMSYS.2007.4433060","url":null,"abstract":"This paper explores the use of dielectric barrier discharge (DBD) surface activated low-temperature wafer bonding in MEMS device fabrication. Characterization of the DBD surface treatment process is included as well as analysis of the optimal bonding conditions. A new high aspect-ratio MEMS technology based on bonding two silicon wafers with an intermediate silicon dioxide layer at 400degC is presented. This silicon-on-silicon (SOS) process requires three masks and provides several advantages compared with silicon-on-glass (SOG) and silicon-on- insulator (SOI) processes, including better dimensional and etch profile control of narrow and slender MEMS structures. This is demonstrated by fabricating a 5 mum wide 30 mm long beam. Additionally, by patterning the intermediate SiO2 insulation layer before bonding, footing is reduced without any extra processing, as compared to both SOG and SOI. All SOS process steps are CMOS compatible.","PeriodicalId":6388,"journal":{"name":"2007 IEEE 20th International Conference on Micro Electro Mechanical Systems (MEMS)","volume":"18 1","pages":"309-312"},"PeriodicalIF":0.0,"publicationDate":"2007-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"87067880","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
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