Microscopic metavehicles powered and steered by embedded optical metasurfaces

Nanostructured dielectric metasurfaces offer unprecedented opportunities to manipulate light by imprinting an arbitrary phase gradient on an impinging wavefront1. This has resulted in the realization of a range of flat analogues to classical optical components, such as lenses, waveplates and axicons2–6. However, the change in linear and angular optical momentum7 associated with phase manipulation also results in previously unexploited forces and...