Photomechanical vibration energy harvesting based on liquid crystal elastomer cantilever

Due to the coupling of external light stimuli with mechanical deformation, light induced responses of liquid crystal elastomer (LCE) cantilevers have been widely studied considering the prospective application in light energy harvesting devices. In this paper, a theoretical study about photomechanical vibration of a LCE cantilever is presented for the further application in energy harvester design. The emphasis is placed on the clarification of light induced inhomogeneous strain distribution on the cantilever responses. Through introducing the physical neutral surface deviation, the governing equation is reformed. The equations are solved by using the superposition method and the Duhamel integral. An empire equation for the maximum tip deflection of the cantilever with respect to characteristic parameters is formulated. The results show that the light induced inhomogeneous strain distribution could not be ignored. The predicted critical values to trigger cantilever vibration agree with the experiment result. This work paves a way to the accurate design of light harvester, light-driven actuators and sensors.