We study the bending of a two-layer piezoelectric semiconductor plate(bimorph).The macroscopic theory of piezoelectric semiconductors is employed.A set of two-dimensional plate equations is derived from the three-dime...We study the bending of a two-layer piezoelectric semiconductor plate(bimorph).The macroscopic theory of piezoelectric semiconductors is employed.A set of two-dimensional plate equations is derived from the three-dimensional equations.The plate equations exhibit direct couplings among bending,electric polarization along the plate thickness,and mobile charges.In the case of pure bending,a combination of physical and geometric parameters is identified which characterizes the strength of the interaction between the mechanical load and the distribution of mobile charges.In the bending of a rectangular plate under a distributed transverse mechanical load,it is shown that mobile charge distributions and potential barriers/wells develop in the plate.When the mechanical load is local and self-balanced,the induced carrier distributions and potential barriers/wells are also localized near the loading area.The results are fundamentally useful for mechanically manipulating mobile charges in piezoelectric semiconductor devices.展开更多
Artificial biomaterials with dynamic mechano-responsive behaviors similar to those of biological tissues have been drawing great attention.In this study,we report a TiO_(2)-based nanowire(TiO_(2)NWs)scaffolds,which ex...Artificial biomaterials with dynamic mechano-responsive behaviors similar to those of biological tissues have been drawing great attention.In this study,we report a TiO_(2)-based nanowire(TiO_(2)NWs)scaffolds,which exhibit dynamic mechano-responsive behaviors varying with the number and amplitude of nano-deformation cycles.It is found that the elastic and adhesive forces in the TiO_(2)NWs scaffolds can increase significantly after multiple cycles of nano-deformation.Further nanofriction experiments show the triboelectric effect of increasing elastic and adhesive forces during the nano-deformation cycles of TiO_(2)NWs scaffolds.These properties allow the TiO_(2)NW scaffolds to be designed and applied as intelligent artificial biomaterials to simulate biological tissues in the future.展开更多
The shape of comparable tissues and organs is consistent among individuals of a given species,but how this consistency or robustness is achieved remains an open question.The interaction between morphogenetic factors d...The shape of comparable tissues and organs is consistent among individuals of a given species,but how this consistency or robustness is achieved remains an open question.The interaction between morphogenetic factors determines organ formation and subsequent shaping,which is ultimately a mechanical process.Using a computational approach,we show that the epidermal layer is essential for the robustness of organ geometry control.Specifically,proper epidermal restriction allows organ asymmetry maintenance,and the tensile epidermal layer is sufficient to suppress local variability in growth,leading to shape robustness.The model explains the enhanced organ shape variations in epidermal mutant plants.In addition,differences in the patterns of epidermal restriction may underlie the initial establishment of organ asymmetry.Our results show that epidermal restriction can answer the longstanding question of how cellular growth noise is averaged to produce precise organ shapes,and the findings also shed light on organ asymmetry establishment.展开更多
The present work investigates the thermally controlled deformation characteristics in temperature-sensitive hydrogels bilayers.The free energy density for temperature-sensitive hydrogels is modified,upon which the fin...The present work investigates the thermally controlled deformation characteristics in temperature-sensitive hydrogels bilayers.The free energy density for temperature-sensitive hydrogels is modified,upon which the finite element model is developed and implemented through user-defined material subroutine UHYPER in the commercial software ABAQUS.The modified UHYPER implementation allows for more vividly depicting the continuous deformation in phase temperature region for temperature-sensitive hydrogels.Several thermally controlled cases of temperature-sensitive hydrogel including grippers,self-folding boxes,thermally driven origami are presented to illustrate a wide array of complex interesting applications or phenomena.Furthermore,we develop a simple model to theoretically calculate the bending angle of the temperature-sensitive hydrogel bilayers,which has been validated by the finite element simulation results.Our study can provide more insights for optimal design in thermally controlled hydrogels structures.展开更多
基金Project supported by the National Natural Science Foundation of China(Nos.12072167 and 11972199)the Natural Science Foundation of Zhejiang Province of China(Nos.LZ22A020001 and LGG19A020001)。
文摘We study the bending of a two-layer piezoelectric semiconductor plate(bimorph).The macroscopic theory of piezoelectric semiconductors is employed.A set of two-dimensional plate equations is derived from the three-dimensional equations.The plate equations exhibit direct couplings among bending,electric polarization along the plate thickness,and mobile charges.In the case of pure bending,a combination of physical and geometric parameters is identified which characterizes the strength of the interaction between the mechanical load and the distribution of mobile charges.In the bending of a rectangular plate under a distributed transverse mechanical load,it is shown that mobile charge distributions and potential barriers/wells develop in the plate.When the mechanical load is local and self-balanced,the induced carrier distributions and potential barriers/wells are also localized near the loading area.The results are fundamentally useful for mechanically manipulating mobile charges in piezoelectric semiconductor devices.
基金supported by the National Natural Science Foundation of China(No.52205198)the Ningbo Natural Science Foundation(No.202003N4091)Ministry of Education of Key Laboratory of Impact and Safety Engineering at Ningbo University(No.CJ202108).
文摘Artificial biomaterials with dynamic mechano-responsive behaviors similar to those of biological tissues have been drawing great attention.In this study,we report a TiO_(2)-based nanowire(TiO_(2)NWs)scaffolds,which exhibit dynamic mechano-responsive behaviors varying with the number and amplitude of nano-deformation cycles.It is found that the elastic and adhesive forces in the TiO_(2)NWs scaffolds can increase significantly after multiple cycles of nano-deformation.Further nanofriction experiments show the triboelectric effect of increasing elastic and adhesive forces during the nano-deformation cycles of TiO_(2)NWs scaffolds.These properties allow the TiO_(2)NW scaffolds to be designed and applied as intelligent artificial biomaterials to simulate biological tissues in the future.
基金We thank Dr.Taku Takahashi for atml-1 pdf2-1 seeds.The authors have no conflicts of interest to declare.This work was supported by National Natural ScienceFoundation of China(31825002,31861130355,and11972200)a Key Research Project of the FrontierScience of the Chinese Academy of Sciences Grant(ZDBS-LY-SM012)to Y.J.
文摘The shape of comparable tissues and organs is consistent among individuals of a given species,but how this consistency or robustness is achieved remains an open question.The interaction between morphogenetic factors determines organ formation and subsequent shaping,which is ultimately a mechanical process.Using a computational approach,we show that the epidermal layer is essential for the robustness of organ geometry control.Specifically,proper epidermal restriction allows organ asymmetry maintenance,and the tensile epidermal layer is sufficient to suppress local variability in growth,leading to shape robustness.The model explains the enhanced organ shape variations in epidermal mutant plants.In addition,differences in the patterns of epidermal restriction may underlie the initial establishment of organ asymmetry.Our results show that epidermal restriction can answer the longstanding question of how cellular growth noise is averaged to produce precise organ shapes,and the findings also shed light on organ asymmetry establishment.
基金The authors are grateful for the support by National Natural Science Foundation of China under Grant Nos.11902167 and 12072167the special research funding from the Marine Biotechnology and Marine Engineering Discipline Group in Ningbo University。
文摘The present work investigates the thermally controlled deformation characteristics in temperature-sensitive hydrogels bilayers.The free energy density for temperature-sensitive hydrogels is modified,upon which the finite element model is developed and implemented through user-defined material subroutine UHYPER in the commercial software ABAQUS.The modified UHYPER implementation allows for more vividly depicting the continuous deformation in phase temperature region for temperature-sensitive hydrogels.Several thermally controlled cases of temperature-sensitive hydrogel including grippers,self-folding boxes,thermally driven origami are presented to illustrate a wide array of complex interesting applications or phenomena.Furthermore,we develop a simple model to theoretically calculate the bending angle of the temperature-sensitive hydrogel bilayers,which has been validated by the finite element simulation results.Our study can provide more insights for optimal design in thermally controlled hydrogels structures.