光驱动液晶聚合物振动器研究进展

Research progress in light-driven oscillators of liquid-crystalline polymers

光响应液晶聚合物在光化学(如偶氮苯)或者光热(如氧化石墨烯)作用下发生有序-无序转变,进而产生宏观形变,是一类被广泛研究的智能材料。目前光驱动液晶聚合物振动器的实现主要有两种途径一是紫外或者可见光连续照射时,偶氮苯液晶聚合物的力学特性发生非线性变化,驱动器呈现无规振动;二是通过构筑非平衡系统,利用驱动器运动过程中的自遮挡效应,在光源连续照射下自发地产生周期性、连续性运动,可用于光学信号调制、移动机器人、能量转换、轧机、马达等。本文综述了光驱动液晶聚合物振动器领域的研究进展,详细介绍了其设计原理、运动机理以及应用领域,对未来的发展趋势做出了展望。

Photo-responsive liquid-crystalline polymers(LCPs)containing photoisomerizable molecular switches(such as azobenzene,AZ)or photothermal agents(such as graphene),are a type of widely investigated smart materials,which can undergo an order-disorder transition,inducing a macroscopic shape change.Presently,light-driven oscillators of LCPs have been achieved mainly by two methods.One is that the actuator displays chaotic swing for the nonlinear change of mechanical properties of LCPs containing AZs under continuous UV or visible light illumination.The other is constructing nonequilibrium systems and relying on the self-shadowing effect during motion.The actuator can realize periodical and sustained motion without additional manual control components,which can be extensively exploited in light signal modulation,mobile robots,energy harvesting,mills,motors,etc.This paper reviews the research progress of light-driven oscillators of LCPs in the past few years,and also introduces its fabrication methods,motion mechanisms and application areas in details.Finally,it provides a view of prospective of its future development trend for light-driven oscillators of LCPs.