Gold Nanoparticles Incorporated Nematic Gel Micropillars Capable of Laser Actuation at Room Temperature

Abstract

Liquid crystal elastomers (LCEs) capable of rapid reversible shape change and ease of actuation at room temperature are highly desired. In this study, a photothermally actuated system based on LCE gel micropillars incorporated with gold nanoparticles is reported for the first time. The photothermal conversion effects of gold nanoparticles (AuNPs) have been studied with a focus on nanoparticle shape (rods and spheres) and loading content. Upon swelling in low molecular mass liquid crystal solvent, the formation of LCE and LCE/AuNP gel enables the reduction of nematic-to-isotropic phase transition temperature (TNI), which allows the gelled micropillar capable of photothermal actuation at room temperature. It has been demonstrated that the LCE gel micropillar with incorporation of 1.0 wt % of gold nanorods can achieve a rapid 30% change in volume within 3 s when under proper laser irradiation at room temperature. The observed discontinuous volumetric transition of the gel micropillars is in good agreement wi...