Photo‐Programmed Deformations in Rigid Liquid Crystalline Polymers Triggered by Body Temperature

Abstract

Deformations triggered by body heat are desirable in the context of shape‐morphing applications because, under the majority of circumstances, the human body maintains a higher temperature than that of its surroundings. However, at present, this bioenergy‐triggered action is primarily limited to soft polymeric networks. Thus, herein, the programming of body temperature‐triggered deformations into rigid azobenzene‐containing liquid crystalline polymers (azo‐LCPs) with a glass‐transition temperature of 100 °C is demonstrated. To achieve this, a mechano‐assisted photo‐programming strategy is used to create a metastable state with room‐temperature stable residual stress, which is induced by the isomerization of azobenzene. The programmed rigid azo‐LCP can undergo large‐amplitude body temperature‐triggered shape changes within minutes and can be regenerated without any performance degradation. By changing the programming photomasks and irradiation conditions employed, various 2D to 3D shape‐morphing architectures, including folded clips, inch‐worm structures, spiral structures, and snap‐through motions are achieved. When programmed with polarized light, the proposed strategy results in domain‐selective activation, generating designed characteristics in multi‐domain azo‐LCPs. The reported strategy is therefore expected to broaden the applications of azo‐LCPs in the fields of biomedical and flexible microelectronic devices.