Biomimetic low-temperature contracting fiber for high stroke and controllable actuations

Abstract

Flexible actuators have significant potential in intelligent micromachines, artificial muscle, and soft robotics. However, achieving actuators with high actuation performance and feedback sensitivity remains challenging. Inspired by the dual “command-execution-feedback” of the mimic octopus, a fiber actuator with high stroke and visual-electronic dual feedback is designed by introducing an ionic liquid conductive network and a visual component of spiropyrane. By constructing a unique interchain slipping structure inside the liquid crystal elastomer (LCE), the nematic to isotropic transition temperature and maximum stroke temperature dropped to 24.29 °C and 62.3 °C, with decreases of 73.51% and 39.28%, respectively. Besides, the actuation stroke increases to 43.41% with an improvement of 77.11%, and the feedback sensitivity reaches to 69.17, along with a high work capacity of 189.12 kJ/m3. These provide a promising strategy for next-generation flexible actuators capable of high work capacity, large stroke, and real-time feedback.