Energy Transfer from the Liquid Crystal Bulk to the Surface Enables Dynamic Topographies via Anisotropic Plasticized Networks

Abstract

Surfaces with dynamic topographies play a pivotal role in modern technology by providing adaptable surface properties in functional coatings. Here, a method for creating dynamic surface topographies with high deformation amplitude using plasticized liquid crystal polymeric networks is proposed. Low molecular weight liquid crystal 5CB is selected as the plasticizer, which is then integrated into the liquid crystal polymer networks (LCNs) and the liquid crystal oligomer networks with longer main chains (LCONs). Upon actuation, the plasticized LCN coating reaches an amplitude of 30%, which is 14% larger than that of the pure LCN system. While the plasticized LCON coating exhibits a significant amplitude of close to 70%, over 37% greater than that of the pure LCONs. The plasticized LCONs exhibit more pronounced deformations than the plasticized LCNs due to their greater flexibility. A physical model explaining the underlying deformation mechanism is further developed. The applications of these dynamic surfaces in optical devices, facilitating transitions between specular reflections and diffuse reflections, or diffraction are demonstrated.