Ultrarobust and Lightweight Electro-Pneumatic Actuators for Soft Robotics

Zean Yuan, Jiaxing Li, Lifu Liu, Xinyu Zhu, Wenbiao Wang, Michael D. Dickey, Guo Zhan Lum, Pakpong Chirarattananon, Jun Luo, Rui Chen

Abstract: Rigid robots can achieve precise motions but expose shortcomings in system complexity, fabrication cost, and human–robot interaction, which motivates researchers to develop various soft robots to fill these gaps. Electro-hydraulic actuators (EHAs) have received widespread attention and been used in many soft robots due to impressive high-strain, fast-speed, and rapid-response characteristics. However, existing EHAs face challenges in achieving large-deformation, high-robustness, and low-weight simultaneously. This limits the application of EHAs in robotic systems that are weight-sensitive or require fail-safe and fault-tolerant behavior. Here, we present a lightweight (0.98 g) electro-pneumatic actuator (EPA) filled with air and only 0.1-mL liquid dielectric, which achieves high-speed bending from 11° to 93.5° in 60 ms, large-angle bending from 11° to 104° in 2 s (the largest in current EHAs), and high-frequency swing at 20 Hz. The EPA is ultrarobust and can operate properly after being punctured by four needles or crushed twice by a 1500-kg vehicle. Furthermore, to validate the above features of EPAs, three applications are demonstrated at a voltage of 6 kV, including four-finger grippers, fast-crawling robots, and water-walking robots. This work pushes the boundaries of robustness and lightweight for EHAs, providing a foundation for the application of electro-pneumatic actuation in soft robotics.

External IDs:dblp:journals/trob/YuanLLZWDLCLC25