A Handheld Laser Soft Welding Process for the Homogeneous Repair and Modular Assembly of Soft Robots

ABSTRACT An efficient, low‐cost, and homogeneous repair and assembly process is crucial for extending the service life and functions of soft robots. Herein, a handheld laser soft welding process is proposed for efficient and low‐cost repair and modular assembly of soft robots. Due to the directional photothermal effect of the laser and the high photothermal conversion efficiency of carbon nanotube additives, the process realizes the rapid liquid‐solid conversion of thermosetting and thermoplastic polymers under laser irradiation, which can be used for the repair and assembly of soft robots. The experimental results show that after the fractured polydimethylsiloxane (PDMS) and thermoplastic elastomer (TPE) are repaired by a handheld laser, their tensile strength can reach more than 91% of that of the undamaged materials. Moreover, the process can complete the repair of samples within 1 min, indicating its high efficiency. Furthermore, the process is used to repair a fractured inchworm‐shaped soft robot and restore its movement function. Meanwhile, an inchworm‐shaped robot and a turtle‐shaped robot are assembled into a dual‐mode biomimetic soft robot using the laser soft welding process, obtaining more flexible motion modes and sensing functions. Thus, the process provides a new promising approach for the repair and functional expansion of soft robots.