4D Printing of magneto- and thermo-responsive, adaptive and multimodal soft robots

This study reports a set of adaptive and multimodal soft robots made of magneto-responsive shape memory polymers (MRSMPs) and magneto-responsive elastomers. A mechanically guided 4D printing method is proposed for programming the continuous and anisotropic magnetisation profiles of MRSMPs. Based on this method, two kinds of magneto- and thermo-responsive, adaptive and multimodal soft robots using MRSMPs are fabricated. They exhibit multiple locomotion modes including crawling, rolling and waving, under different magneto- and thermo-stimulations, and possess excellent functionalities such as objects transportation. The Young's modulus of robots can change across orders of magnitude (0.2–500 MPa). Further, the multi-legged robot can change its locomotion mode in response to different stimulations, including a special walking mode realised by the smooth swing of legs. The robot can move in any direction on the ground smoothly and stably under the walking mode, and the stride can be precisely tuned from 2.6 to 8.4 mm. Our robots may find more applications in complex unstructured engineering environments by virtue of its multimodal locomotion and excellent adaptive performance.