晶态材料中的挠曲电效应:现状与展望

Flexoelectricity in Crystalline Materials: Status and Perspective

挠曲电效应描述的是应变梯度诱导的电极化现象以及电场梯度诱导的材料应变现象。该效应作为一类特殊的力电耦合效应,具有不受材料对称性限制、不受材料居里温度限制以及小尺寸效应等特点,广泛存在于液晶、生物材料、介质材料(如钛酸钡陶瓷)中,具有非常重要的传感和驱动应用前景。本文重点综述了过去10余年间挠曲电理论、实验以及应用研究进展,对挠曲电的机理进行了讨论,同时对未来挠曲电的发展提出了展望。

Flexoelectricity,referring to the electric polarization induced by mechanical strain gradient or mechanical strain induced by electric field gradient,has drawn considerable research interest due to its great potential in sensing and actuating application.As a unique electro-mechanical effect,it has many features such as scaling effect,no symmetry limitation and no Curie temperature limitation.It has been found that the flexoelectricity can be widely existed in liquid crystal,biological materials and dielectrics(such as barium titanate ceramic).This paper mainly reviewed the past ten year progress of flexoelectricity covering flexoelectric theory,flexoelectric experiment and flexoelectric application.The physical origin and the perspective of flexoelectricity were also discussed in this review.