A new method for MEMS dynamics analysis is presented,ased on the similarity theory. With this method, two systems' similarities can be captured in terms of physics quantities/governed-equations amongst different e...A new method for MEMS dynamics analysis is presented,ased on the similarity theory. With this method, two systems' similarities can be captured in terms of physics quantities/governed-equations amongst different energy fields, and then the unknown dynamic characteristics of one of the systems can be analyzed according to the similar ones of the other system. The probability to establish a pair of similar systems among MEMS and other energy systems is also discussed based on the equivalent between mechanics and electrics, and then the feasibility of applying this method is proven by an example, in which the squeezed damping force in MEMS and the current of its equivalent circuit established by this method are compared.展开更多
This study describes a novel micro proton exchange membrane fuel cell(PEMFC)(active area,2.5 cm2).The flow field plate is manufactured by applying micro-electromechanical systems(MEMS) technology to silicon substrates...This study describes a novel micro proton exchange membrane fuel cell(PEMFC)(active area,2.5 cm2).The flow field plate is manufactured by applying micro-electromechanical systems(MEMS) technology to silicon substrates to etch flow channels without a gold-coating.Therefore,this investigation used MEMS technology for fabrication of a flow field plate and presents a novel fabrication procedure.Various operating parameters,such as fuel temperature and fuel stoichiometric flow rate,are tested to optimize micro PEMFC performance.A single micro PEMFC using MEMS technology reveals the ideal performance of the proposed fuel cell.The optimal power density approaches 232.75 mW·cm-1 when the fuel cell is operated at ambient condition with humidified,heated fuel.展开更多
The field of micro-electro-mechanical systems(MEMS) has advanced tremendously for the last 20 years.Most commercially noticeably,the field has successfully advanced from pressure sensors to micro physical sensors,such...The field of micro-electro-mechanical systems(MEMS) has advanced tremendously for the last 20 years.Most commercially noticeably,the field has successfully advanced from pressure sensors to micro physical sensors,such as accelerometers and gyros,for handheld electronics application.In parallel,MEMS has also advanced into micro total analysis system(TAS) and/or lab-on-a-chip applications.This article would discuss a relatively new but promising future direction towards MEMS biomedical implants.Specifically,Parylene C has been explored to be used as a good MEMS implant material and will be discussed in detail.Demonstrated implant devices,such as retinal and spinal cord implants,are presented in this article.展开更多
Recent research has revealed a remarkable diversity of viruses in archaeal-rich environments where spindles, spheres, fila- ments and rods are common, together with other exceptional morphotypes never recorded previou...Recent research has revealed a remarkable diversity of viruses in archaeal-rich environments where spindles, spheres, fila- ments and rods are common, together with other exceptional morphotypes never recorded previously. Moreover, their dou- ble-stranded DNA genomes carry very few genes exhibiting homology to those of bacterial and eukaryal viruses. Studies on viral life cycles are still at a preliminary stage but important insights are being gained especially from microarray analyses of viral transcripts for a few model virus-host systems. Recently, evidence has been presented for some exceptional archaeal- nspecific mechanisms for extra-cellular morphological development of virions and for their cellular extrusion. Here we sum- marise some of the recent developments in this rapidly developing and exciting research area.展开更多
文摘A new method for MEMS dynamics analysis is presented,ased on the similarity theory. With this method, two systems' similarities can be captured in terms of physics quantities/governed-equations amongst different energy fields, and then the unknown dynamic characteristics of one of the systems can be analyzed according to the similar ones of the other system. The probability to establish a pair of similar systems among MEMS and other energy systems is also discussed based on the equivalent between mechanics and electrics, and then the feasibility of applying this method is proven by an example, in which the squeezed damping force in MEMS and the current of its equivalent circuit established by this method are compared.
基金Supported by the National Science Council (NSC 97-2221-E-009-067)
文摘This study describes a novel micro proton exchange membrane fuel cell(PEMFC)(active area,2.5 cm2).The flow field plate is manufactured by applying micro-electromechanical systems(MEMS) technology to silicon substrates to etch flow channels without a gold-coating.Therefore,this investigation used MEMS technology for fabrication of a flow field plate and presents a novel fabrication procedure.Various operating parameters,such as fuel temperature and fuel stoichiometric flow rate,are tested to optimize micro PEMFC performance.A single micro PEMFC using MEMS technology reveals the ideal performance of the proposed fuel cell.The optimal power density approaches 232.75 mW·cm-1 when the fuel cell is operated at ambient condition with humidified,heated fuel.
文摘The field of micro-electro-mechanical systems(MEMS) has advanced tremendously for the last 20 years.Most commercially noticeably,the field has successfully advanced from pressure sensors to micro physical sensors,such as accelerometers and gyros,for handheld electronics application.In parallel,MEMS has also advanced into micro total analysis system(TAS) and/or lab-on-a-chip applications.This article would discuss a relatively new but promising future direction towards MEMS biomedical implants.Specifically,Parylene C has been explored to be used as a good MEMS implant material and will be discussed in detail.Demonstrated implant devices,such as retinal and spinal cord implants,are presented in this article.
基金supported by grants from the Danish Natural Science Research Councilthe Danish Council of Technology and Production+1 种基金the Danish Foundation for Basic Researchthe European Union
文摘Recent research has revealed a remarkable diversity of viruses in archaeal-rich environments where spindles, spheres, fila- ments and rods are common, together with other exceptional morphotypes never recorded previously. Moreover, their dou- ble-stranded DNA genomes carry very few genes exhibiting homology to those of bacterial and eukaryal viruses. Studies on viral life cycles are still at a preliminary stage but important insights are being gained especially from microarray analyses of viral transcripts for a few model virus-host systems. Recently, evidence has been presented for some exceptional archaeal- nspecific mechanisms for extra-cellular morphological development of virions and for their cellular extrusion. Here we sum- marise some of the recent developments in this rapidly developing and exciting research area.
