Morphing LCE surface coatings with topological defects: simulation studies*

Stimuli-responsive liquid crystal elastomers (LCE) with patterned molecular orientation morph in response to any stimulus that affects nematic order. We model shape-morphing in temperature-responsive dynamic thin film coatings with patterned disclinations oriented either parallel or perpendicular to the surface normal. For short disclinations perpendicular to the surface, we find that arrays of +/- 1 defects give rise to profiles with dimples or spikes depending on whether defects are radial or azimuthal. By altering defect core structure we design a flat coating that transforms to an array of suction cups resembling octopus suckers, e.g. to create temperature-driven adhesion. We also model LCE coatings with disclinations parallel to the surface, formed between substrates with antagonistic anchoring patterns. We model formation of the resulting microstructure under antagonistic alignment, and morphing of the coating on heating to form an array of microchannels. We compare theory and modeling studies with recent experiments [1-2] and discuss potential applications. [1] Babakhanova et al Nat Commun 9, 456 (2018). [2] Babakhanova et al, Journal of Applied Physics, in press.