Figure 5.

Fabrication process of microscale magnetic tumbling motors ($\mathsf{\mu }$TUM). (a) Photolithography process followed for the the fabrication of $\mathsf{\mu }$TUM. (b) Magnetic particle alignment techniques. Magnets located above the robot result in alignment along the geometric z-axis and sideways tumbling (ST); magnets located beside the robot result in alignment along the geometric x-axis and lengthwise tumbling (LT). (c) Optical images of the different geometric variations on the $\mathsf{\mu }$TUM ending sections that have been explored: (i) rounded corners, (ii) sharp corners, (iii) triangles and (iv) (asymmetric) rounded rectangles. Scale bar, 300 $\mathsf{\mu }$m.