I highly recommend looking into Marc's work [0]. I would say he's on the sharp end of lithography for microrobotics. As soft lithography catches on more, work like his will become only more common to see.

[0]: https://miskinlab.seas.upenn.edu/

See also:

“Microscopic robots that sense, think, act, and compute” by Marc Miskin https://www.youtube.com/watch?v=ks22prQ8F4c