Light-Induced Bending and Buckling of Large-Deflected Liquid Crystalline Polymer Plates

Abstract

Cross-linked liquid crystalline polymers (LCPs) are smart materials for large light-activated variation or bend to transfer luminous energy into mechanical energy. We study the light-induced behavior of homeotropic nematic network polymer plates. The perturbation method is applied to find approximate solutions under uniform illumination and compared with finite element simulations. Moreover, situations of nonuniform laser illumination are investigated. Unlike single solution obtained from small displacement assumption, multiple solutions within Föppl–von Kármán nonlinear geometry framework are found in the post-buckling regime and the effect of various boundary conditions is discussed. The nonuniform bending moment generated by the inhomogeneous light-induced strain, membrane force and boundary effects lead to the unconventional nonsymmetric buckling behavior that is rarely observed under traditional mechanical or thermal loading.