Self-Sensing Actuators Based on a Stiffness Variable Reversible Shape Memory Polymer Enabled by a Phase Change Material

• DOI: 10.1021/acsami.2c07119
• Publication Date: 2022-05-06T17:23:46Z
• Authors: Zhao Xu; Dun-Wen Wei; Rui-Ying Bao; Yu Wang; Kai Ke; Ming-Bo Yang; Wei Yang
• Keywords: 02 engineering and technology; 0210 nano-technology

Soft actuators with integrated mechanical and actuation properties and self-sensing ability are still a challenge. Herein, a stiffness variable polyolefin elastomer (POE) with a reversible shape memory effect is prepared by introducing a typical phase change material, i.e., paraffin wax (PW). It is found that the variable stiffness of POE induced by PW can balance the reversible strain and load-bearing capability of actuators. Especially, carbon nanotubes (CNTs) are concentrated in a thin surface layer by spraying and hot pressing in the soft state of POE/PW blends, providing signal transductions for the strain and temperature perception for actuators. Taking advantage of tunable reversible deformation and mechanical transformation of the POE/PW actuator, different biomimetic robotics, including grippers with high load-bearing capability (weight-lifting ratio > 146), walking robots that can sense angles of joints, and high-temperature warning robots are demonstrated. A scheme combining the variable stiffness and electrical properties provides a versatile strategy to integrate actuation performance and self-sensing ability, inspiring the development of multifunctional composite designs for soft robotics.