Multifunctional Liquid Crystal Polymer Network Soft Actuators
Multifunctionality is an essential feature for the application of soft actuators in the fields of soft robotics, flexible electronics, and energy generators. Liquid crystal polymer networks (LCNs) afford a promising platform for designing multifunctional soft actuators due to their reversible, programmable, and multi-stimuli-responsive shape changing behaviors via self-organization of liquid crystals. Although the introduction of functional components (e.g. conductive or magnetic fillers) has been considered an effective approach to exploit multifunctional LCN soft actuators, it remains a grand challenge to integrate particular role of functional components meanwhile maintaining inherent shape changing capabilities of LCNs. Herein, we report a facile method to achieve multifunctional LCN soft actuators by directly injecting desired functional component of liquid state into LCN tubular actuators. In our design, LCN tubular actuators prepared by the mechanical programming process take the role of structural framework providing reversible shape changing behaviors with a large strain both in the length and inner diameter. For introducing conductive functionality, liquid metals (LMs) are selected as functional component due to ultrahigh conductivity and controllable melting point. The multifunctional LCN soft actuators elegantly couple ultrahigh conductivity of LMs and original shape changing behaviors of LCN tubular actuators and are demonstrated as a thermal-responsive electrical switch.