Acoustic Assembly Photopolymerization of Bioinspired Multimaterial Hierarchical Films With Programmable Adhesion

Abstract

Abstract Devices with stimuli-responsiveness, programmable and reversible adhesion, and adaptability to uneven surfaces have attracted extensive attention for applications such as microgrippers and soft robots. Despite recent advances, challenges still exist in rapid shape morphing, noncontact control, and reversible switching between attachment and detachment. Fundamentally, those challenges are owing to the material limitation, manufacturing constraints, and design complexity involved in the production of those devices. To overcome these challenges, we report a simple and rapid manufacturing approach, acoustic assembly photopolymerization (AAP), for the production of magnetic-responsive devices with programmable and reversible adhesion. The proposed AAP process provides an environmentally sustainable approach to fabricating micro- to macroscale multimaterial films with hierarchical surface features within seconds. The locally controlled composition enables precise magnetic control, while the flexible hierarchical surface structures allow rapid attachment and detachment. The combined effects of material and structural composition enable remarkable control over the adhesive property without requiring any complicated treatment and power source. In this work, a photocurable magnetic composite material was developed, and the adhesion programmability of the printed films was investigated. As a proof of concept, test cases were performed, including soft magnetic robots and untethered grippers. The results indicated the promising applications of such AAP-printed films, with the advantages of programmable adhesion, locally engineered flexibility, rapid, and remote noncontact magnetic actuation. The AAP manufacturing capability and the proposed multimaterial hierarchical film design possess a broad range of applications, including surface engineering, soft robotics, and microfluidics.