SEM images of a microwalker from (a) bottom and (b) side view. Scale bar: 10 μm. (c) Top row shows the initial state of microwalkers on different surfaces. Bottom row shows the microwalker randomly walking, rotating, walking with self-reorientation, and walking along certain direction. (d) Molecules used in the experiment on different surfaces. Insets of the top row show the schematics of the surface. Reprinted with permission from Ref. [75].