Soft electronics,which are designed to function under mechanical deformation(such as bending,stretching,and folding),have become essential in applications like wearable electronics,artificial skin,and brain-machine in...Soft electronics,which are designed to function under mechanical deformation(such as bending,stretching,and folding),have become essential in applications like wearable electronics,artificial skin,and brain-machine interfaces.Crystalline silicon is one of the most mature and reliable materials for high-performance electronics;however,its intrinsic brittleness and rigidity pose challenges for integrating it into soft electronics.Recent research has focused on overcoming these limitations by utilizing structural design techniques to impart flexibility and stretchability to Si-based materials,such as transforming them into thin nanomembranes or nanowires.This review summarizes key strategies in geometry engineering for integrating crystalline silicon into soft electronics,from the use of hard silicon islands to creating out-of-plane foldable silicon nanofilms on flexible substrates,and ultimately to shaping silicon nanowires using vapor-liquid-solid or in-plane solid-liquid-solid techniques.We explore the latest developments in Si-based soft electronic devices,with applications in sensors,nanoprobes,robotics,and brain-machine interfaces.Finally,the paper discusses the current challenges in the field and outlines future research directions to enable the widespread adoption of silicon-based flexible electronics.展开更多
A turbocharged diesel engine model was built with the GT-Power software,and experimentally verified.Then two different control variables for the control of the variable geometry turbocharger（VGT）were described,and t...A turbocharged diesel engine model was built with the GT-Power software,and experimentally verified.Then two different control variables for the control of the variable geometry turbocharger（VGT）were described,and their distinct effects on engine performance,i.e.NOxand soot emissions and fuel consumption,were simulated and compared on the basis of this model.The results showed that NOxemissions decreased obviously with the increase of exhaust gas recirculation（EGR）rate at constant boost pressure condition,but soot emissions and fuel consumption considerably increased.It was a good way to reduce NOxemissions without increasing fuel consumption and soot emissions when VGT was controlled to maintain the excess oxygen ratio unchanged as EGR rate increases.展开更多
An optically levitated nanoparticle in a vacuum provides an ideal platform for ultra-precision measurements and fundamental physics studies because of the exceptionally high-quality factor and rich motion modes,which ...An optically levitated nanoparticle in a vacuum provides an ideal platform for ultra-precision measurements and fundamental physics studies because of the exceptionally high-quality factor and rich motion modes,which can be engineered by manipulating the optical field and the geometry of the nanoparticle.Nanofabrication technology with the ability to create arbitrary nanostructure arrays offers a precise way of engineering the optical field and the geometry of the nanoparticle.Here,for the first time,we optically levitate and rotate a nanofabricated nanorod via a nanofabricated a-Si metalens which strongly focuses a 1550 nm laser beam with a numerical aperture of 0.953.By manipulating the laser beam’s polarization,the levitated nanorod’s translation frequencies can be tuned,and the spin rotation mode can be switched on and off.Then,we showed the control of rotational frequency by changing the laser beam’s intensity and polarization as well as the air pressure.Finally,a MHz spin rotation frequency of the nanorod is achieved in the experiment.This is the first demonstration of controlled optical spin in a metalens-based compact optical levitation system.Our research holds promise for realizing scalable on-chip integrated optical levitation systems.展开更多
基金the National Natural Science Foundation of China under granted No.62104100National Key Research Program of China under No.92164201+1 种基金National Natural Science Foundation of China for Distinguished Young Scholars under No.62325403National Natural Science Foundation of China under No.61934004.
文摘Soft electronics,which are designed to function under mechanical deformation(such as bending,stretching,and folding),have become essential in applications like wearable electronics,artificial skin,and brain-machine interfaces.Crystalline silicon is one of the most mature and reliable materials for high-performance electronics;however,its intrinsic brittleness and rigidity pose challenges for integrating it into soft electronics.Recent research has focused on overcoming these limitations by utilizing structural design techniques to impart flexibility and stretchability to Si-based materials,such as transforming them into thin nanomembranes or nanowires.This review summarizes key strategies in geometry engineering for integrating crystalline silicon into soft electronics,from the use of hard silicon islands to creating out-of-plane foldable silicon nanofilms on flexible substrates,and ultimately to shaping silicon nanowires using vapor-liquid-solid or in-plane solid-liquid-solid techniques.We explore the latest developments in Si-based soft electronic devices,with applications in sensors,nanoprobes,robotics,and brain-machine interfaces.Finally,the paper discusses the current challenges in the field and outlines future research directions to enable the widespread adoption of silicon-based flexible electronics.
基金Supported by Diesel Engine Development Program of MIIT(DEDP-1004)Natural Science Foundation of BIT(3030012211428)
文摘A turbocharged diesel engine model was built with the GT-Power software,and experimentally verified.Then two different control variables for the control of the variable geometry turbocharger（VGT）were described,and their distinct effects on engine performance,i.e.NOxand soot emissions and fuel consumption,were simulated and compared on the basis of this model.The results showed that NOxemissions decreased obviously with the increase of exhaust gas recirculation（EGR）rate at constant boost pressure condition,but soot emissions and fuel consumption considerably increased.It was a good way to reduce NOxemissions without increasing fuel consumption and soot emissions when VGT was controlled to maintain the excess oxygen ratio unchanged as EGR rate increases.
文摘An optically levitated nanoparticle in a vacuum provides an ideal platform for ultra-precision measurements and fundamental physics studies because of the exceptionally high-quality factor and rich motion modes,which can be engineered by manipulating the optical field and the geometry of the nanoparticle.Nanofabrication technology with the ability to create arbitrary nanostructure arrays offers a precise way of engineering the optical field and the geometry of the nanoparticle.Here,for the first time,we optically levitate and rotate a nanofabricated nanorod via a nanofabricated a-Si metalens which strongly focuses a 1550 nm laser beam with a numerical aperture of 0.953.By manipulating the laser beam’s polarization,the levitated nanorod’s translation frequencies can be tuned,and the spin rotation mode can be switched on and off.Then,we showed the control of rotational frequency by changing the laser beam’s intensity and polarization as well as the air pressure.Finally,a MHz spin rotation frequency of the nanorod is achieved in the experiment.This is the first demonstration of controlled optical spin in a metalens-based compact optical levitation system.Our research holds promise for realizing scalable on-chip integrated optical levitation systems.
