Fully Recyclable, Healable, Soft, and Stretchable Dynamic Polymers for Magnetic Soft Robots

Abstract

AbstractMagnetic soft robots capable of wirelessly controlled programmable deformation and locomotion are desirable for diverse applications. Such multi‐variable actuation ideally requires a polymer matrix with a well‐defined range of softness and stretchability (Young's modulus of 0.1–10 MPa, high stretchability >200%). However, this defined mechanical range excludes most polymer candidates, leaving only a limited number of available polymers (e.g., PDMS, Ecoflex) with covalently cross‐linked networks that may lead to non‐recyclable robots and further potential threats to environment. Herein, based on the synergistic effects of reduced cross‐linking density and intermolecular hydrogen bonding, a dynamic covalent polyimine is newly designed as polymer matrix and magnetic microparticles as fillers, and integrate defined softness and stretchability, full chemical recyclability, rapid room‐temperature healability and multimodal actuation into a single magnetic soft robot. The polyimine is soft and stretchable enough to process soft robots in various geometries by simple laser cutting, without the need to pre‐design the geometry to suit target scenarios. Through a cyclic depolymerization/repolymerization, this full recycling restores 100% of the robots’ mechanical properties and rapid deformability/mobility to their original level within seconds and heals quickly within minutes when damaged, facilitating ideal cyclic material economy for soft robots in diverse scenarios.