Recyclable silicone elastic light-triggered actuator with a reconfigurable Janus structure and self-healable performance

Silicone rubber is a type of elastomer that possesses excellent biocompatibility and a good resistance to high and low temperatures and can be used as the matrix of smart materials in the biomedical field. As one of the attractive functions of smart materials, their regional shape transformation behavior under multiple stimuli is very useful. In order to produce silicone elastomers with these characteristics, a special structure such as a Janus structure is usually required. Herein, a novel strategy to prepare a silicone elastic light-triggered actuator with a Janus structure has been developed, which was fabricated via heterogeneous crosslinking induced by a gradient intensity of UV light due to carbon nanotube (CNT) accretion. By tailoring the geometric shapes, the region and time of the UV irradiation and the location of the stimulus, the Janus membranes can be programmed with multiple types of deformations and exhibit a shape transformation triggered by organic solvent or laser irradiation. Additionally, the membrane can be readily switched between Janus and homogeneous structures due to the reversible dimerization of anthracene, resulting in the reconfiguration of the membrane. Meanwhile, the composite membrane exhibits an excellent self-healing ability at 60 °C, or even room temperature, and can be recycled repeatedly via the hot-pressing or solution casting methods because of the introduction of reversible imine bonds into the crosslinked networks. This strategy provides significant guidance for the design of self-healable and reconfigurable soft biocompatible actuators, and so forth.