Loget G., Kuhn A.
Nature Comm. 20112, 535

Externally triggered motion of small objects shows a general promise in applications ranging from micromachines to drug delivery and self-assembly of superstructures. Here we present a new concept for the controlled propulsion of conducting objects with sizes ranging from centimeters to hundreds of micrometers. It is based on their polarization, induced by an electric field. This triggers spatially separated oxidation and reduction reactions involving asymmetric gas bubble formation, which leads to a directional motion of the objects. Depending upon the implied redox chemistry and the device design, the speed can be controlled and the motion can be switched from linear to rotational. This type of chemical locomotion is an alternative to the so far existing approaches based on different other principles.