A high mechanical strength, self-healing silicone elastomer for thin film thermal actuator

Thin film actuator has the advantages of simple construction and repaid responses. However, once damaged, it makes them face great challenges in terms of performance stability. Here, a self-healing thermal actuator was developed by combining a self-healing silicone elastomer with a polyimide film. The silicone elastomer with excellent self-healing and high mechanical properties was designed by triple dynamic reversible bond of hydrogen bond, oxime bond, and metal coordination bond. Polyurea groups provided a large number of cross-linking points for supramolecular hydrogen bonding, and nitrogen atoms on the oxime group form complexes with various metal ions (such as Cu 2+ , Zn 2+ , Fe 3+ ), which can significantly improve its mechanical strength (up to 4818 kPa). Silicone elastomer exhibited fast and efficient self-healing properties (99.9% within 10 h at room temperature) based on a triple dynamic reversible bond. In addition, the actuator can be thermally driven and achieve a maximum bend of 59.9° at 100 °C. The actuator shows excellent cyclic stability in the range of 100 cycles, and can still achieve the original bending angle after healing. The realization of self-healing performance on flexible actuators provides the experimental basis for the further development of artificial muscles.