Curvature by design and on demand in liquid crystal elastomers

TL;DR

This paper demonstrates how to design and induce specific curvature patterns in liquid crystal elastomers (LCEs) using spatial director variations, enabling controlled shape transformations for practical applications.

Contribution

It introduces a new design strategy for LCEs that allows shape control and stress-free anchoring, advancing their use in shape-shifting devices.

Findings

Good agreement between predicted and observed curvatures.

Imprinted spiral patterns effectively induce desired shapes.

Anchoring method prevents internal stresses during actuation.

Abstract

The shape of liquid crystalline elastomers (LCEs) with spatial variation in the director orientation can be transformed by exposure to a stimulus. Here, informed by previously reported analytical treatments, we prepare complex spiral patterns imprinted into LCEs and quantify the resulting shape transformation. Quantification of the stimuli-induced shapes reveals good agreement between predicted and experimentally observed curvatures. We conclude this communication by reporting a design strategy to allow LCE films to be anchored at their external boundaries onto rigid substrates without incurring internal, mechanical-mismatch stresses upon actuation, a critical advance to the realization of shape transformation of LCEs in practical device applications.