Chenzhe Li

Achieving programmable morphing in 3D‐to‐3D shapes of soft actuators based on liquid crystal elastomer (LCE), particularly those with multimodal transformations and non‐zero Gaussian curvature, remains a significant challenge. Here, a facile strategy is presented to create 3D LCE‐elastomer (LCE‐Ela) bilayer structures capable of customizable and programmable 3D‐to‐3D shape transformations, generating reversible and multimodal morphologies with nonzero Gaussian curvature. By combining two types of mismatch strains—pre‐stretch and thermal strains—in LCE‐Ela bilayer, the approach enables hierarchical multimodal transformations: starting from a 2D initial configuration, programmable transformations enable the formation of complex 3D structures, which can subsequently transition into other 3D shapes following predefined programs, with each step of the hierarchical process allowing multimodal deformations to generate diverse structural morphologies. Experimental and computational demonstrations include over 30 diverse 3D LCE‐Ela configurations, the majority of which exhibit nonzero Gaussian curvature. Moreover, biomimetic LCE‐Ela structures—including a chameleon, butterfly, spider, and leaf—demonstrate vivid deformation and discoloration, showcasing their potential for applications such as information encryption, camouflage, and adaptive devices. This work provides a facile approach to generate customizable 3D‐to‐3D transformations with complex geometries, broadening the application scope of LCE‐based technologies in 3D soft actuators.

Azobenzene-incorporated liquid crystalline polymer (azo-LCP), which undergo property change and deformation upon Ultra violet and visible light stimulation, are promising materials in various fields. This study investigated the effect of azobenzene concentration on photosoftening based on the photoisomerization of an azo-LCP. The experimental results confirmed that as the azobenzene concentration increased, the order parameter decreased and mechanical properties deteriorated. Photoisomerization and photosoftening was also conducted on an azo-LCP unit cell constructed by molecular dynamics simulation. The simulation results showed that changes in the order parameter, length contraction and elastic modulus due to the photosoftening, in alignment with the experimental results.

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.