Experimental Investigation of a Thermally Responsive Actuator Based on Metallic Molybdenum Disulfide: A Conceptual Analysis

Abstract

Actuators that convert external stimuli to mechanical energy have aroused strong attention for emerging applications in robotics, artificial muscles, and other fields. However, their limited performance under harsh operating conditions evidenced by the low cycle life and hysteresis has restricted their practical applications. Here, a thermaldriven actuator based on layered metallic molybdenum disulfide (1T MoS2) nanosheets is demonstrated. The active actuator film exhibits fully reversible and highly stable (>99.296% in 2700 cycles) thermalmechanical conversion over a wide temperature window (from −60 °C to 80 °C). Importantly, 1T MoS2 film shows a fast response with the bending rate and the recovery rate of >1.090 rad s−1 and >0.978 rad s−1, respectively. The assembled actuator can lift 20 times its weight over several centimeters for more than 200 cycles. This work, for the first time, demonstrates the thermoresponsive characteristics of 1T MoS2 in developing the thermal actuator, which may open new opportunities for various applications, such as robotics, artificial muscles, and human assist devices.