Pub Date : 2003-09-01DOI: 10.1142/S1465876303001484
F. Chollet, C. Low, Sok Kim Lee, Chun Yang
The development of micro-optical bench (MOB) technology as so far been limited by its reliance on polysilicon based elements which does not have good optical properties, and does not easily yield the spherical surfaces needed for refracting lenses. Polymers have shown large improvement in the recent years and could be a solution to hasten the development of MOB. We report here on the fabrication using polymers of converging and diverging refracting lens, with diameter ranging between 60 μm and 500 μm and with focal length as small as 100 μm. The polymer investigated where a photosensible cresol novolak (AZ9260), a photosensible epoxy resin (SU8) and a silicone (PDMS). In addition we have developed a phenomenological model and a physical model that elucidate the relationship between the fabrication parameters and the characteristics of the optical elements.
{"title":"Fabrication Of Concave And Convex Micro-Optical Elements With Polymer For Free-Space Micro-Optical Bench","authors":"F. Chollet, C. Low, Sok Kim Lee, Chun Yang","doi":"10.1142/S1465876303001484","DOIUrl":"https://doi.org/10.1142/S1465876303001484","url":null,"abstract":"The development of micro-optical bench (MOB) technology as so far been limited by its reliance on polysilicon based elements which does not have good optical properties, and does not easily yield the spherical surfaces needed for refracting lenses. Polymers have shown large improvement in the recent years and could be a solution to hasten the development of MOB. We report here on the fabrication using polymers of converging and diverging refracting lens, with diameter ranging between 60 μm and 500 μm and with focal length as small as 100 μm. The polymer investigated where a photosensible cresol novolak (AZ9260), a photosensible epoxy resin (SU8) and a silicone (PDMS). In addition we have developed a phenomenological model and a physical model that elucidate the relationship between the fabrication parameters and the characteristics of the optical elements.","PeriodicalId":331001,"journal":{"name":"Int. J. Comput. Eng. Sci.","volume":"167 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2003-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"123595746","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 : 2003-09-01DOI: 10.1142/S1465876303001897
Y. Murakoshi, X. Shan, R. Maeda
MEMS (Micro Electro Mechanical Systems) products are being spread from laboratory to industries. But Silicon-based MEMS products are usually expensive and not suitable for low cost production. Hence, there is an emerging need in terms of cost effectiveness to transfer MEMS from silicon-based materials to other materials, such as glasses and polymers. Micro hot embossing is expected to be a novel technique for producing MEMS components/products with low cost, and will potentially find wide applications in micro fluidics, biomedical and micro optical areas. In this paper, a hot embossing instrument is illustrated and is used for the process development of micro/nano structure forming with polycarbonate (PC) and Polyetheretherketone (PEEK) by using the Nickel mold. Fabrications of micro vertical reflecting mirrors and cantilevers for an 8×8 optical switch have been carried out, replication of micro grooves and pyramid cavities with nanometer precision for passive alignment of optical fibers and micro ball lenses have been performed as well. The results show that hot embossing is a promising technology for cost effective micro/nano fabrications of MEMS.
{"title":"Application Of Micro Hot Embossing For MEMS Structures","authors":"Y. Murakoshi, X. Shan, R. Maeda","doi":"10.1142/S1465876303001897","DOIUrl":"https://doi.org/10.1142/S1465876303001897","url":null,"abstract":"MEMS (Micro Electro Mechanical Systems) products are being spread from laboratory to industries. But Silicon-based MEMS products are usually expensive and not suitable for low cost production. Hence, there is an emerging need in terms of cost effectiveness to transfer MEMS from silicon-based materials to other materials, such as glasses and polymers. Micro hot embossing is expected to be a novel technique for producing MEMS components/products with low cost, and will potentially find wide applications in micro fluidics, biomedical and micro optical areas. In this paper, a hot embossing instrument is illustrated and is used for the process development of micro/nano structure forming with polycarbonate (PC) and Polyetheretherketone (PEEK) by using the Nickel mold. Fabrications of micro vertical reflecting mirrors and cantilevers for an 8×8 optical switch have been carried out, replication of micro grooves and pyramid cavities with nanometer precision for passive alignment of optical fibers and micro ball lenses have been performed as well. The results show that hot embossing is a promising technology for cost effective micro/nano fabrications of MEMS.","PeriodicalId":331001,"journal":{"name":"Int. J. Comput. Eng. Sci.","volume":"382 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2003-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"115478658","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 : 2003-09-01DOI: 10.1142/S1465876303001551
A. Pandey, R. Pratap
Structural vibration studies of various MEMS structures have revealed that whenever a suspended flat structure vibrates normal to a fixed substrate with a very small gap between the two surfaces, the squeeze film damping due to fluid present in the gap dominates the dissipation mechanism by orders of magnitude compared with other losses. Since the quality factor is a critical parameter in the design of MEMS devices and it depends on damping, a careful evaluation of the squeeze film damping is necessary. The most often used formulas for evaluating this damping, due to Blech and Griffins, are based on the linearized Reynolds equation. These formulas are applicable for small amplitude oscillations. In this paper, we consider all nonlinear terms in the governing equation of the flow between the plates and study the effects of these terms on the damping characteristics. We show that as the amplitude of vibration increase, the damping force increases faster than the spring force of the fluid and, therefore, the cut-off frequency changes nonlinearly.
{"title":"Studies In Nonlinear Effects Of Squeeze Film Damping In Mems Structures","authors":"A. Pandey, R. Pratap","doi":"10.1142/S1465876303001551","DOIUrl":"https://doi.org/10.1142/S1465876303001551","url":null,"abstract":"Structural vibration studies of various MEMS structures have revealed that whenever a suspended flat structure vibrates normal to a fixed substrate with a very small gap between the two surfaces, the squeeze film damping due to fluid present in the gap dominates the dissipation mechanism by orders of magnitude compared with other losses. Since the quality factor is a critical parameter in the design of MEMS devices and it depends on damping, a careful evaluation of the squeeze film damping is necessary. The most often used formulas for evaluating this damping, due to Blech and Griffins, are based on the linearized Reynolds equation. These formulas are applicable for small amplitude oscillations. In this paper, we consider all nonlinear terms in the governing equation of the flow between the plates and study the effects of these terms on the damping characteristics. We show that as the amplitude of vibration increase, the damping force increases faster than the spring force of the fluid and, therefore, the cut-off frequency changes nonlinearly.","PeriodicalId":331001,"journal":{"name":"Int. J. Comput. Eng. Sci.","volume":"2 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2003-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"122065078","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 : 2003-09-01DOI: 10.1142/S1465876303002040
A. Fang, Hian Kee Lee, Suresh Valiyaveeti
It is highly desirable to develop a phosphine-free recyclable heterogenous catalytic system without the use of expensive and air-sensitive basic phosphines for palladium-catalysed coupling reactions. Nano-palladium catalysts for example, in various stabilised forms have been extensively explored as potential alternatives to achieve a higher catalytic activity. In line with the great interest directed towards the development of microfabricated chemical systems for a variety of chemical and biological applications, we demonstrate here a microreactor based on microfluidic channels on glass chips for the continous flow organic synthesis using immobilised nano-palladium. The palladium colliods were immobilised on the inner-walls of the microchannels via an intermediate organosilane monolayer. The covalent attachment of colloidal palladium provides minimum leaching of the catalyst. The Suzuki coupling of an aryl halide and an organoboron has been used a model system to investigate the performance characteristic...
{"title":"Microfluidic Channels Modified With Collodial Palladium As An Efficient Catalyst For High Throughput Suzuki Coupling Reactions","authors":"A. Fang, Hian Kee Lee, Suresh Valiyaveeti","doi":"10.1142/S1465876303002040","DOIUrl":"https://doi.org/10.1142/S1465876303002040","url":null,"abstract":"It is highly desirable to develop a phosphine-free recyclable heterogenous catalytic system without the use of expensive and air-sensitive basic phosphines for palladium-catalysed coupling reactions. Nano-palladium catalysts for example, in various stabilised forms have been extensively explored as potential alternatives to achieve a higher catalytic activity. In line with the great interest directed towards the development of microfabricated chemical systems for a variety of chemical and biological applications, we demonstrate here a microreactor based on microfluidic channels on glass chips for the continous flow organic synthesis using immobilised nano-palladium. The palladium colliods were immobilised on the inner-walls of the microchannels via an intermediate organosilane monolayer. The covalent attachment of colloidal palladium provides minimum leaching of the catalyst. The Suzuki coupling of an aryl halide and an organoboron has been used a model system to investigate the performance characteristic...","PeriodicalId":331001,"journal":{"name":"Int. J. Comput. Eng. Sci.","volume":"15 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2003-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"125957468","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 : 2003-09-01DOI: 10.1142/S1465876303001964
Yuanzhi Lao, F. Tay, Guolin Xu, Diana Hartono, Y. Y. Lee
A micro thermocycling chip has been developed, which is able to achieve high heating and cooling rates of over 16°C/s and 9.6°C/s respectively using the induction heating method. The heating element of the micro thermocycler was fabricated through electroplating on glass. SU-8 and Polydimethyl-siloxane (PDMS) are used to form the reaction chamber. DSP base servo controller was selected for close loop control the reaction chamber temperature. The thermocycler chip's properties, such as non-contact heating method, rapid cycling speed and PC control, make it suitable to integrate into clinical molecular diagnostic devices and point-of-care devices.
{"title":"A Non-Contact Micro Thermocycling Chip For Polymerase Chain Reactions","authors":"Yuanzhi Lao, F. Tay, Guolin Xu, Diana Hartono, Y. Y. Lee","doi":"10.1142/S1465876303001964","DOIUrl":"https://doi.org/10.1142/S1465876303001964","url":null,"abstract":"A micro thermocycling chip has been developed, which is able to achieve high heating and cooling rates of over 16°C/s and 9.6°C/s respectively using the induction heating method. The heating element of the micro thermocycler was fabricated through electroplating on glass. SU-8 and Polydimethyl-siloxane (PDMS) are used to form the reaction chamber. DSP base servo controller was selected for close loop control the reaction chamber temperature. The thermocycler chip's properties, such as non-contact heating method, rapid cycling speed and PC control, make it suitable to integrate into clinical molecular diagnostic devices and point-of-care devices.","PeriodicalId":331001,"journal":{"name":"Int. J. Comput. Eng. Sci.","volume":"5 21 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2003-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"124790852","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 : 2003-09-01DOI: 10.1142/S1465876303001794
J. Li, Q. Zhang, A. Liu
A new thin film technique is proposed and demonstrated in this paper to prevent the notching effect on silicon on insulator (SOI) wafer micromachinig. SOI wafer provides decisive features. However, the notching effect or undercutting due to the charges built up at the surface of the buried insulation layer degrades the structures and performances of the devices. In this paper, a thin oxide film is introduced combining with multiple steps of etching to prevent the notching effect. To verify this idea, a mask with trenches from 0.4 to 20 μm was designed and the etching was carried out on SOI wafer with 35 μm device silicon layer. The etching result showed that the approach proposed is very effective on notching effect.
{"title":"Prevent Notching For Soi Microstructure Fabrication Using SIO2 Thin Film Technique","authors":"J. Li, Q. Zhang, A. Liu","doi":"10.1142/S1465876303001794","DOIUrl":"https://doi.org/10.1142/S1465876303001794","url":null,"abstract":"A new thin film technique is proposed and demonstrated in this paper to prevent the notching effect on silicon on insulator (SOI) wafer micromachinig. SOI wafer provides decisive features. However, the notching effect or undercutting due to the charges built up at the surface of the buried insulation layer degrades the structures and performances of the devices. In this paper, a thin oxide film is introduced combining with multiple steps of etching to prevent the notching effect. To verify this idea, a mask with trenches from 0.4 to 20 μm was designed and the etching was carried out on SOI wafer with 35 μm device silicon layer. The etching result showed that the approach proposed is very effective on notching effect.","PeriodicalId":331001,"journal":{"name":"Int. J. Comput. Eng. Sci.","volume":"182 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2003-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"121409895","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 : 2003-09-01DOI: 10.1142/S1465876303001836
Guangya Zhou, F. Tay, Chau Fook Siong
This paper presents the development of a reduced-order macro-model for a two-axis electrostatic torsional micromirror using analog hardware description language (AHDL). The proposed macro-model permits extremely fast simulation while providing nearly FEM accuracy. This enables the user to investigate the close-loop controlled global system level performances at acceptable computational cost.
{"title":"Modeling Of A Two-Axis Torsional Micromirror Using Ahdl","authors":"Guangya Zhou, F. Tay, Chau Fook Siong","doi":"10.1142/S1465876303001836","DOIUrl":"https://doi.org/10.1142/S1465876303001836","url":null,"abstract":"This paper presents the development of a reduced-order macro-model for a two-axis electrostatic torsional micromirror using analog hardware description language (AHDL). The proposed macro-model permits extremely fast simulation while providing nearly FEM accuracy. This enables the user to investigate the close-loop controlled global system level performances at acceptable computational cost.","PeriodicalId":331001,"journal":{"name":"Int. J. Comput. Eng. Sci.","volume":"104 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2003-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"123060110","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 : 2003-09-01DOI: 10.1142/S1465876303002052
C. Iliescu, Tietun Sun, J. Miao, F. Tay
This paper purposes a very simple and reliable fabrication process foar a silicon capacitive microphone, the two electrodes of the condenser microphone are: a thin p++ silicon membrane fabricated using an optimized diffusion process, and a thick -30 μm - top electrode, processed also on a silicon wafer. Isolating and metal layers assure the gap between those two eletrodes. The bonding between electrode's wafers is performed using an Au-Si eutectic wafer-to-wafer bonding techniques. The thinning of top-electrode was made in the same step of the process as the etching of silicon diaphragm. The concept of fabrication process was to avoid the sticking of thin diaphragm to top electrode during different wet process. Different design with different size of diaphragm was fabricated using this process. The resulting capacitance was in the range of 1.85-3.5 pF.
{"title":"Fabrication Process Of A Capacitive Microphone With p++ Diaphragm And Silicon Bonded Top-Plate","authors":"C. Iliescu, Tietun Sun, J. Miao, F. Tay","doi":"10.1142/S1465876303002052","DOIUrl":"https://doi.org/10.1142/S1465876303002052","url":null,"abstract":"This paper purposes a very simple and reliable fabrication process foar a silicon capacitive microphone, the two electrodes of the condenser microphone are: a thin p++ silicon membrane fabricated using an optimized diffusion process, and a thick -30 μm - top electrode, processed also on a silicon wafer. Isolating and metal layers assure the gap between those two eletrodes. The bonding between electrode's wafers is performed using an Au-Si eutectic wafer-to-wafer bonding techniques. The thinning of top-electrode was made in the same step of the process as the etching of silicon diaphragm. The concept of fabrication process was to avoid the sticking of thin diaphragm to top electrode during different wet process. Different design with different size of diaphragm was fabricated using this process. The resulting capacitance was in the range of 1.85-3.5 pF.","PeriodicalId":331001,"journal":{"name":"Int. J. Comput. Eng. Sci.","volume":"PP 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2003-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"126401996","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 : 2003-09-01DOI: 10.1142/S1465876303001915
R. Dhote, S. Chiluveru, S. Chandorkar, P. Apte
MEMS based heatuators are being used extensively for actuation purpose. The conventional heatuators have different arm widths while this paper proposes a variant design that has equal widths but unequal resistances. The new design brings in the advantages of faster response and greater deflections for similar condition. The heatuators have been simulated using the coupled-fied element SOLID98 of the finite element analysis software ANSYS.
{"title":"A Novel Heatuator","authors":"R. Dhote, S. Chiluveru, S. Chandorkar, P. Apte","doi":"10.1142/S1465876303001915","DOIUrl":"https://doi.org/10.1142/S1465876303001915","url":null,"abstract":"MEMS based heatuators are being used extensively for actuation purpose. The conventional heatuators have different arm widths while this paper proposes a variant design that has equal widths but unequal resistances. The new design brings in the advantages of faster response and greater deflections for similar condition. The heatuators have been simulated using the coupled-fied element SOLID98 of the finite element analysis software ANSYS.","PeriodicalId":331001,"journal":{"name":"Int. J. Comput. Eng. Sci.","volume":"27 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2003-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"127571891","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 : 2003-09-01DOI: 10.1142/S1465876303001927
Wei Zhang, X. Yao, Xiaoqing Wu
This paper presents a new preparation scheme of monolithic pyroelectric thin film infrared sensor. The sensor can be prepared directly on readout circuit and its electrode can be connected to the readout circuit through a via. PbTiO3 thin film is used as pyroelectric material. Porous SiO2 thin film is applied onto silicon wafer to improve the thermal isolation of the pyroelectric layer. Copper interconnection is used in readout circuit to solve the problem that aluminium interconnection can't endure the annealing temperature of PbTiO3 thin film.
{"title":"Novel Preparation Scheme Of Monolithic Pyroelectric Thin Film Infrared Sensor","authors":"Wei Zhang, X. Yao, Xiaoqing Wu","doi":"10.1142/S1465876303001927","DOIUrl":"https://doi.org/10.1142/S1465876303001927","url":null,"abstract":"This paper presents a new preparation scheme of monolithic pyroelectric thin film infrared sensor. The sensor can be prepared directly on readout circuit and its electrode can be connected to the readout circuit through a via. PbTiO3 thin film is used as pyroelectric material. Porous SiO2 thin film is applied onto silicon wafer to improve the thermal isolation of the pyroelectric layer. Copper interconnection is used in readout circuit to solve the problem that aluminium interconnection can't endure the annealing temperature of PbTiO3 thin film.","PeriodicalId":331001,"journal":{"name":"Int. J. Comput. Eng. Sci.","volume":"151 10","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2003-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"114049609","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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