Recyclable and Photothermal Free-Standing Adhesive Tape toward Reconfigurable Soft Actuators

Abstract

Soft actuators have shown great potential in soft robotic technologies, where complex functions usually originate from fundamental components with a simple motion mode. Therefore, how to convert the simple motion mode to complex motion modes becomes a vital challenge. In contrast to rigid actuators, where the simple motion mode can be converted to complex motion modes by gearing systems and transmission devices, manufacturing assembled soft actuators by splicing different functional building blocks has been considered an effective strategy. However, most of the assembled soft actuators cannot be reconstructed and modified once they have been fabricated because of the limitation of the adhesion methods, making these devices unmodifiable and unreconfigurable and typically thrown away after a single use. Endowing the assembled materials with well-designed functions that the components do not have by designing functional adhesives is also important. Considering that free-standing adhesive tapes can have the features of onsite and repeatable installation and can be integrated with designed functions and shapes, devising assembled actuators using adhesive tape appears to be a feasible approach. Herein, we develop a free-standing functional adhesive tape based on polydisulfides containing photoresponsive azobenzene moieties (PDS-Azo) and utilize the tape to fabricate reconfigurable and spliceable soft actuators. The chemical structures of PDS-Azo tape are carefully designed to obtain an optimized adhesion performance with photothermal functions. Moreover, the tape could show reversible adhesion triggered by either heating or light irradiation. It is demonstrated that the adhesive tape can be utilized to assemble different functional building blocks to develop smart soft devices with reconfigurability.