Universal converse flexoelectricity in dielectric materials via varying electric field direction  

作　　者：Saurav Sharma Rajeev Kumar Rahul Vaish 

机构地区：[1]School of Engineering,Indian Institute of Technology Mandi,Mandi,India

出　　处：《International Journal of Smart and Nano Materials》2021年第1期107-128,共22页国际智能和纳米材料杂志（英文）

摘　　要：Flexoelectricity is a symmetry independent electromechanical cou-pling phenomenon that outperforms piezoelectricity at micro and nanoscales due to its size-dependent behavior arising from gradi-ent terms in its constitutive relations.However,due to this gradient term flexoelectricity,to exhibit itself,requires specially designed geometry or material composition of the dielectric material.First of its kind,the present study put forward a novel strategy of achieving electric field gradient and thereby converse flexoelectri-city,independent of geometry and material composition of the material.The spatial variation of the electric field is established inside the dielectric material,Ba_(0.67)Sr_(0.33)TiO_(3)(BST),by manipulating electrical boundary conditions.Three unique patterns of electrode placement are suggested to achieve this spatial variation.This varying direction of electric field gives rise to electric field gradient,the prerequisite of converse flexoelectricity.A multi-physics cou-pling based theoretical framework is established to solve the flexo-electric actuation by employing isogeometric analysis(IGA).Electromechanically coupled equations of flexoelectricity are solved to obtain the electric field distribution and the resulting displace-ments thereby.The maximum displacements of 0.2 nm and 2.36 nm are obtained with patterns I and II,respectively,while pattern III can yield up to 85 nm of maximum displacement.

关 键 词：Converse flexoelectricity electrical boundary conditions electric field direction isogeometric analysis 

分 类 号：O17[理学—数学]