Nowadays,the demand for advanced functional materials in transducer technology is growing rapidly.Piezoelectric materials transform mechanical variables(displacement or force)into electrical signals(charge or voltage)...Nowadays,the demand for advanced functional materials in transducer technology is growing rapidly.Piezoelectric materials transform mechanical variables(displacement or force)into electrical signals(charge or voltage)and vice versa.They are interesting from both fundamental and application points of view.Ferrooelectrets(also called piezoelectrets)are a relatively young group of piezo-,pyro-and ferroelectric materials.They exhibit ferroic behavior phenomenologically undistinguishable from that of traditional ferroelectrics,although the materials per se are essentially non-polar space-charge electrets with artificial macroscopic dipoles(i.e.,internally charged cavities).A lot of work has been done on ferroelectrets and their applications up to now.In this paper,we review and discuss mostly the work done at University of Potsdam on the research and development of ferroelectrets.We will,however,also mention important results from other teams,and prospect the challenges and future progress trend of the field of ferroelectret research.展开更多
Surface acoustic wave(SAW)gas sensors based on the acoustoelectric effect exhibit wide application prospects for in situ gas detection.However,establishing accurate models for calculating the scattering parameters of ...Surface acoustic wave(SAW)gas sensors based on the acoustoelectric effect exhibit wide application prospects for in situ gas detection.However,establishing accurate models for calculating the scattering parameters of SAW gas sensors remains a challenge.Here,we present a coupling of modes(COM)model that includes the acoustoelectric effect and specifically explains the nonmonotonic variation in the center frequency with respect to the sensing film’s sheet conductivity.Several sensing parameters of the gas sensors,including the center frequency,insertion loss,and phase,were experimentally compared for accuracy and practicality.Finally,the frequency of the phase extremum(FPE)shift was determined to vary monotonically,and the range of selectable test points was wide,making the FPE an appropriate response parameter for leveraging in SAW gas sensors.The simulation results of the COM model were highly consistent with the experimental results.Our study is proposed to provide theoretical guidance for the future development of gas SAW sensors.展开更多
基金Financial support from the National Natural Science Foundation of China(No.12174102)the National Key Research and Development Program of China(No.2021YFC3001802)the Shanghai Program for Professor of Special Appointment(Eastern Scholar)at Shanghai Institutions of Higher Learning,and Shanghai Key Laboratory of Special Artificial Microstructure Materials and Technology is gratefully acknowledged.
文摘Nowadays,the demand for advanced functional materials in transducer technology is growing rapidly.Piezoelectric materials transform mechanical variables(displacement or force)into electrical signals(charge or voltage)and vice versa.They are interesting from both fundamental and application points of view.Ferrooelectrets(also called piezoelectrets)are a relatively young group of piezo-,pyro-and ferroelectric materials.They exhibit ferroic behavior phenomenologically undistinguishable from that of traditional ferroelectrics,although the materials per se are essentially non-polar space-charge electrets with artificial macroscopic dipoles(i.e.,internally charged cavities).A lot of work has been done on ferroelectrets and their applications up to now.In this paper,we review and discuss mostly the work done at University of Potsdam on the research and development of ferroelectrets.We will,however,also mention important results from other teams,and prospect the challenges and future progress trend of the field of ferroelectret research.
基金supported by the National Key Research and Development Program of China(Grant No.2022YFA1204603)the Shenzhen Science and Technology Innovation Program(Grant No.GJHZ20210705142539009)the National Natural Science Foundation of China(Grant No.11874169).
文摘Surface acoustic wave(SAW)gas sensors based on the acoustoelectric effect exhibit wide application prospects for in situ gas detection.However,establishing accurate models for calculating the scattering parameters of SAW gas sensors remains a challenge.Here,we present a coupling of modes(COM)model that includes the acoustoelectric effect and specifically explains the nonmonotonic variation in the center frequency with respect to the sensing film’s sheet conductivity.Several sensing parameters of the gas sensors,including the center frequency,insertion loss,and phase,were experimentally compared for accuracy and practicality.Finally,the frequency of the phase extremum(FPE)shift was determined to vary monotonically,and the range of selectable test points was wide,making the FPE an appropriate response parameter for leveraging in SAW gas sensors.The simulation results of the COM model were highly consistent with the experimental results.Our study is proposed to provide theoretical guidance for the future development of gas SAW sensors.
