Custom-made actuation driven by “smooth yet complex” liquid crystal director microstructures

Liquid crystalline elastomers have demonstrated a rich variety of actuation behavior ranging from in-plane contraction/elongation to out-of-plane twisting, bending, curling, popping-up cones, and other complex morphologies. Analytical techniques have successfully determined custom-made 3-D liquid crystal director configurations that encode the actuation of a thin LCE film to an arbitrary target morphology. Here, we investigate the shape change of a custom-made automobile-shaped actuator. Via fully 3-D finite element elastodynamics simulations of a sample with in-plane geometry and 3-D director microstructure given by custom design, we model the actuator’s shape change and analyze the effect of sample thickness in its stimulus-responsive morphing and final morphology. We found that the sample thickness averages out details of the automobile-morphology while maintaining its overall target shape. In addition, our simulations show a pop-up sequence in the initial morphing of the sample to external stimulus. Similar pop-up morphing behavior has been observed in experiments of thick LCE samples.