4D printing of patterned multimaterial magnetic hydrogel actuators

This paper demonstrates a new class of printable magnetic hydrogels that can be successfully used for multimaterial direct ink printing (4D printing) soft actuators. To date, most reports on actuation have not considered biocompatibility issues associated with materials and synthetic polymers. For this reason, in study, considerable attention was given to developing bionanocomposites exhibit noncytotoxicity hence may biomedical applications. Three inks various concentrations nanoparticles (MNPs) were print 3D objects, such as tubes (wheels), cubes, cantilevers. The interactions between MNPs hydrogel precursor network accounted excellent shear thinning properties the inks. Usually, actuators move or change shape upon anisotropic swelling deswelling, possible only an aqueous environment. Our study addresses challenge by incorporating into hydrogel, allowing contactless in-air control motion. Because high structural integrity we state is method obtaining construct resolution, fidelity, tunable distribution MNPs, induced macroscopic anisotropy. are highly porous noncytotoxic towards fibroblasts but also good mechanical stability unique responsiveness. simple approach allowed us fabricate different patterns, composed non-magnetic materials. results demonstrate interplay nonmagnetic influences performance illustrated magnetically rolling, jumping, bending. It shown programmable patterning leads development macroscopically material. confirmed intersection 4D responsive promises fulfill future robotics' functionality requirements.