Dual‐Stroke Soft Peltier Pouch Motor Based on Pipeless Thermo‐Pneumatic Actuation

Abstract

Soft pneumatic actuators are made of flexible materials that deform in response to pressure changes. Due to their reliability, safety, and flexibility, such actuators enable diverse hardware design and become indispensable for soft robots. However, bulky air compressors and pipes constrain their further integration and lightweight. The liquid–vapor phase transition can produce significant encapsulated volume changes and achieve pipeless thermo‐pneumatic actuation. Herein, a novel soft thermoelectric‐based actuator, named Peltier pouch motor (PPM), is presented with modular and dual‐stroke characteristics enabled by active phase transition of low‐boiling‐point liquid. Furthermore, its lightweight and stretchable compliance contributes to assembly‐induced hyper‐modularity to create diverse degrees‐of‐freedom hybrid systems. Finally, the various forms of PPM units are exploited and versatile locomotion is facilitated for five different applications under multi‐medium scenarios, including thermo‐responsive land locomotion, submersible noise‐free hovering, smart curtains control, body‐temperature‐driven wrist rehabilitation, and adaptive hybrid gripper. In these results, it is indicated that the proposed PPM unit advances in hyper‐modularity with excellent performance in high load rate (around 400%), heat transfer efficiency (heating boost, 425%; cooling boost, 138%), and thermal response performance (heating, 0.57° s−1; cooling, 0.29° s−1; 4.5 V), inspiring widely innovative soft robots through the pipeless thermo‐pneumatic actuation.