Active Pillar Array Structure by Solvent-free Liquid Crystal Elastomer Resin

Bioinspired active pillar structures, known for their large surface area, mechanical compliance, and diverse deformation modes, have garnered extensive research interest. Among various active pillar structures, liquid crystal elastomer (LCE) pillar arrays are capable of exhibiting significant and reversible anisotropic deformation under cyclic heating and cooling, showing great potential in tunable adhesion, soft robots, and biomedical devices. However, scaling up LCE pillar manufacturing remains challenging, limiting its practical applications. In this work, a solvent-free LCE resin is developed with unique features including simple operating procedure, short fabrication time, and tunable responsive temperature, enabling rapid and large-scale production of LCE pillar arrays. The LCE resin allows for the preparation of complex 3D shapes in addition to film or specimen. The fabrication time can be as short as 4 h, without the need to evaporate solvent. Moreover, the LCE resins can be adjusted with a variable phase transition temperature range from 49.4 °C to 97.7 °C by incorporating non-liquid crystal acrylate chains. The resulting active pillar array structure can undertake sequential actuation upon heating with the tunable actuation temperature. Finally, the application of these pillar arrays in multi-level information encryption is demonstrated. The LCE pillar structure introduced here offers a new strategy for constructing advanced active LCE structures with tunable responsive behavior.