Eliciting diverse self-regulated actuation pathways from a compositionally uniform liquid crystalline elastomer microstructure

Traditionally, synthetic microactuator deformations have remained largely simplistic—stemming from uniform responses to stimuli—and non-reconfigurable—as deformations are prescribed through elaborate architectures relying on cumbersome fabrication procedures. Here, we report a conceptually new approach to reconfigurable microactuators: by employing directional stimuli on a single high-aspect-ratio micropost fabricated from compositionally uniform materials (a photoresponsive liquid crystalline elastomer) with tilted directionality, we elicit reversible, multimodal deformations including light-seeking, light-avoiding, clockwise and counterclockwise twisting. By adjusting irradiation conditions, these deformation modes can be turned into non-linear, non-reciprocal, and self-regulated biomimetic actuations. Conceptually, these deformations are made possible by local, directional disruption of order evolving as a traveling order-to-disorder front across the micropillar, deliberate symmetry-breaking, and spontaneously emerging opto-chemo-mechanical feedback loops. The ease of fabrication, unparalleled level of control, and conceptual simplicity bode well for immediate employment of the presented approach in practical applications.