Magnetically Actuated Rolling of Star-Shaped Hydrogel Microswimmer

A magnetically powered, star-shaped poly(vinylalcohol)/alginate (PVA/ALG) hydrogel microswimmer is described as a biodegradable motile vehicle for potential biomedical applications. The star-shaped microswimmer is fabricated by the addition of a mixture containing PVA, ALG, and magnetic nanoparticles in the optimal ratio into the designed star-shape silicon pattern and subsequent gelation of the mixture inside the pattern. This hydrogel microswimmer displays efficient and controllable propulsion in biological media under a vertical rotating magnetic field. Such star-shaped hydrogel microswimmers have excellent biodegradability and mechanical capability and thus show promise in biomedical applications such as drug transport and surgery.