挠曲电效应及其应用研究进展

Recent Development on Flexoelectric Effect and Its Application

挠曲电效应是一种应变梯度与电极化(正挠曲电效应)或电场强度梯度与应变(逆挠曲电效应)之间的力电耦合效应。与压电效应不同,挠曲电效应不受材料对称性、Curie温度所限制,且随着材料尺寸减小而不断增强,因而具有广阔的研究与应用前景。本文主要总结了挠曲电效应的发展历史、挠曲电系数测量、挠曲电效应增强机制以及当前研究进展,重点介绍了挠曲电效应在传感器、致动器、机械存储器、挠曲电压电复合材料、俘能器以及新型电子器件等领域应用的最新研究进展,最后对挠曲电效应的发展前景进行了展望。

The flexoelectric effect is a mechanical-electric coupling effect between strain gradient and electric polarization(i.e.,positive flexoelectric effect)or electric field strength gradient and mechanical strain(i.e.,converse flexoelectric effect).Unlike the piezoelectric effect,the flexoelectric effect,which is not limited by material symmetry and the Curie temperature,increases with decreasing the material size,thus attracting much attention and having a promising application.This review introduced the history of flexoelectric effect,measurement of flexoelectric coefficient,and mechanism to enhance flexoelectric effect.Recent studies on its application in the realm of sensors,actuators,mechanical memories,flexoelectric piezoelectric composites,energy harvesters,and electronic devices were highlighted.In addition,the further development of flexoelectric effect was also prospected.