Fig. 1.

Design and Fabrication process. a) Overview of the microrobot design of length L (80 $\mu$m and 40 $\mu$m ) and diameter D (40 $\mu$m and 20 $\mu$m), respectively. b) 3D printing microrobots on a silicon chip using a two-photon direct laser writing technique. c) Overview of the printed microrobots on the silicon chip after removing the excess resin. d) Illustration of the nickel vapor deposition on the silicon chip. e) The scanning electron microscope image of the nickel-layer deposited microrobot. f) The sectional view of the microrobot with the air bubble in the deionized (DI) water suspension