▎ 摘　　要

Twisted and coiled actuators (TCAs) composed of fishing lines or sewing threads are one of the most promising artificial muscles because of their high specific power, large stroke, and low fabrication cost. Since the TCA can be thermally actuated, the thermal properties of the actuator determine its actuation performance. Here, graphene materials with high thermal conductivity and low thermal mass were used as coating materials on nylon TCA surfaces to enhance the dynamic responses of the TCA. Large-area monolayer graphene and porous graphene foam were wrapped on the TCA surface and provided a reduction of the actuation cycle times by 10.1 and 17.8%, respectively. Furthermore, high-quality multi-layer graphene flakes were spray-coated on the surface of the TCA, showing a dramatic decrease in the cycle time by 30.9%. The enhanced heat transfer due to the graphene flake coating also increased the maximum strain of the TCA over 3 times under a duty cycle of a pulsed current input. This demonstrates an alternative way to improve the dynamic performance of the TCA using a simple coating method.