Soft Spiral-Shaped Micro-Swimmer with Propulsion Force Control by Pitch Change

This paper describes a soft spiral-shaped micro-swimmer with propulsion force controlled by pitch change. Soft spiral-shaped micro-swimmers, made of stimuli-responsive hydrogel encapsulating magnetic nanoparticles, were continuously formed by using a bevel-tip capillary. We achieved the pitch change of the double-layered micro-swimmer by temperature stimulus and confirmed that the propulsion force of the swimmer was controlled by the pitch change. We believe that our micro-swimmer could pave the way to various microscale biochemical applications such as autonomous soft-robots and soft micro-probes for intricate environment.