The nonlinear static characteristic of a piezoelectric unimorph cantilever micro actuator driven by a strong applied electric field is studied based on the couple stress theory.The cantilever actuator consists of a pi...The nonlinear static characteristic of a piezoelectric unimorph cantilever micro actuator driven by a strong applied electric field is studied based on the couple stress theory.The cantilever actuator consists of a piezoelectric layer,a passive（elastic）layer and two electrode layers.First,the nonlinear static characteristic of the actuator caused by the electrostriction of the piezoelectric layer under a strong applied electric field is analyzed using the Rayleigh-Ritz method.Secondly,since the thickness of the cantilever beam is in micro scale and there exists a size effect,the size dependence of the deformation behavior is evaluated using the couple stress theory.The results show that the nonlinearities of the beam deflection increase along with the increase of the applied electric field which means that softening of the micro beam rigidity exists when a strong external electric field is applied.Meanwhile,the optimal value of the thickness ratio for the passive layer and the piezoelectric layer is not around 1.0 which is usually adopted by some previous researchers.Since there exists a size effect of the micro beam deflection,the optimal value of this thickness ratio should be greater than 1.0 in micro scale.展开更多
We study the response of a composite beam(unimorph)with a piezomagnetic layer and a piezoelectric semiconductor layer under a transverse magnetic field.A one-dimensional model for coupled bending and extension of the ...We study the response of a composite beam(unimorph)with a piezomagnetic layer and a piezoelectric semiconductor layer under a transverse magnetic field.A one-dimensional model for coupled bending and extension of the beam is derived from the three-dimensional theory.A simple and analytical solution of the model is obtained,showing that various electromechanical fields develop in the beam through piezomagnetic and piezoelectric couplings as well as semiconduction.In particular,the mobile charges in the semiconductor layer redistribute themselves under the magnetic field.A coupling coefficient is defined to describe the strength of this magneto-semiconduction coupling.The effects of physical and geometric parameters on the fields and the coupling coefficient are examined.The results are fundamental to piezotronics when magnetic effects are involved.展开更多
Deformable mirrors are essential dynamic wavefront compensation.Among the various types of deformable mirrors with different actuation mechanisms,the unimorph piezoelectric deformable mirror(UPDM)offers distinct advan...Deformable mirrors are essential dynamic wavefront compensation.Among the various types of deformable mirrors with different actuation mechanisms,the unimorph piezoelectric deformable mirror(UPDM)offers distinct advantages owing to its compact size and low cost.The two most critical challenges in UPDM are electrode fabrication and deformation control.This study proposes an integrated electrode fabrication and sensorless feedback control scheme for UPDM,which simplifies the manufacturing process and enhances its performance.The electrode array is created using silkscreen printing combined with flexible printed circuit board technology,integrating electrode fabrication and electrical connection into a single step.The desired mirror deformation is achieved by introducing a closed-loop direct deformation control method based on piezoelectric self-sensing.The feedback mechanism utilizes the local strain-induced charge generated by the piezoelectric plate,effectively addressing the nonlinear behavior of the piezoelectric material.Experimental results confirm the feasibility and effectiveness of the proposed method,with the maximum relative error in the steady state phase remaining below 2%.展开更多
基金The National Natural Science Foundation of China(No.10772086,10772085)
文摘The nonlinear static characteristic of a piezoelectric unimorph cantilever micro actuator driven by a strong applied electric field is studied based on the couple stress theory.The cantilever actuator consists of a piezoelectric layer,a passive（elastic）layer and two electrode layers.First,the nonlinear static characteristic of the actuator caused by the electrostriction of the piezoelectric layer under a strong applied electric field is analyzed using the Rayleigh-Ritz method.Secondly,since the thickness of the cantilever beam is in micro scale and there exists a size effect,the size dependence of the deformation behavior is evaluated using the couple stress theory.The results show that the nonlinearities of the beam deflection increase along with the increase of the applied electric field which means that softening of the micro beam rigidity exists when a strong external electric field is applied.Meanwhile,the optimal value of the thickness ratio for the passive layer and the piezoelectric layer is not around 1.0 which is usually adopted by some previous researchers.Since there exists a size effect of the micro beam deflection,the optimal value of this thickness ratio should be greater than 1.0 in micro scale.
基金This work was supported by the National Natural Science Foundation of China(Nos.12072167 and 11972199)the special research funding from the Marine Biotechnology and Marine Engineering Discipline Group in Ningbo University,and the K.C.Wong Magana Fund through Ningbo University.
文摘We study the response of a composite beam(unimorph)with a piezomagnetic layer and a piezoelectric semiconductor layer under a transverse magnetic field.A one-dimensional model for coupled bending and extension of the beam is derived from the three-dimensional theory.A simple and analytical solution of the model is obtained,showing that various electromechanical fields develop in the beam through piezomagnetic and piezoelectric couplings as well as semiconduction.In particular,the mobile charges in the semiconductor layer redistribute themselves under the magnetic field.A coupling coefficient is defined to describe the strength of this magneto-semiconduction coupling.The effects of physical and geometric parameters on the fields and the coupling coefficient are examined.The results are fundamental to piezotronics when magnetic effects are involved.
基金supported in part by the Strategic Priority Research Program of the Chinese Academy of Sciences(XDB1050000)in part by the CAS Project for Young Scientists in Basic Research(YSBR-066)+2 种基金in part by the National Science Foundation of China(T2122001)in part by the capital construction funds within the budget of Jilin Province(2023C030-6)in part by the Youth Innovation Promotion Association of the Chinese Academy of Sciences(Y2021065).
文摘Deformable mirrors are essential dynamic wavefront compensation.Among the various types of deformable mirrors with different actuation mechanisms,the unimorph piezoelectric deformable mirror(UPDM)offers distinct advantages owing to its compact size and low cost.The two most critical challenges in UPDM are electrode fabrication and deformation control.This study proposes an integrated electrode fabrication and sensorless feedback control scheme for UPDM,which simplifies the manufacturing process and enhances its performance.The electrode array is created using silkscreen printing combined with flexible printed circuit board technology,integrating electrode fabrication and electrical connection into a single step.The desired mirror deformation is achieved by introducing a closed-loop direct deformation control method based on piezoelectric self-sensing.The feedback mechanism utilizes the local strain-induced charge generated by the piezoelectric plate,effectively addressing the nonlinear behavior of the piezoelectric material.Experimental results confirm the feasibility and effectiveness of the proposed method,with the maximum relative error in the steady state phase remaining below 2%.
