Controllable Roll-to-Swim motion transition of helical nanoswimmers

Magnetically actuated helical nanoswimmers have various potential applications from in-vitro microfluidics to invivo less invasive surgery. However these applications provide more challenging environments for the helical nanoswimmers by often limiting their mobility robustness from their limited motion dexterity. That is why we propose in this paper a multimodal Roll-to-Swim motion transition of helical nanoswimmers. The proposed Roll-to-Swim is a robust swimmer that takes advantages of both a rolling motion and a cork-screw swimming. The Roll-to-Swim can switch between these two different propulsion modes by simply controlling the direction and the frequency of the rotating magnetic field. We also show that the proposed system can be controlled either manually or by a closed loop with microscopic visual feedback. The system proved to be used for cargo transport of micro scale particles. Thanks to the demonstrated multi-motion transition and the cargo transport capabilities, Roll-to-Swimmers can be very promising and useful tools toward in-vitro microfluidics or in-vivo applications.