Magnetic soft robots composed of stimuli-responsive materials are promising for biomedical engineering applications; however, typical responsive materials are fabricated with nondegradable polymeric substrates. In this study, we report a flexible, biodegradable, and magnetically sensitive cellulose film (M-film) that can be utilized for magnetically controllable soft robots (M-robots) with programmable locomotion, cargo delivery, and remote wireless operation functions. The M-film with good foldability, origami, and magnetic properties is synthesized by a simple paper-making process using cellulose nanofibers, additive sodium alginate, and BaFe12O19 particles. Through the following origami-magnetization process, the M-robot with multimodal movements is designed: climbing over the obstacles in the walking environment; additionally, this process can complete various cargo transport tasks by clawing, rolling, and flipping. This approach expands the precise controllability and manipulability of environmentally friendly cellulose nanomaterials beyond the known applications and opens the prospects of their implementation in stimuli-responsive robots, wireless control electronics, and intelligent devices.
Keywords: cellulose nanofiber; magnetic film; programmable magnetization; soft robot; stimuli-responsive materials.