3-D MEMS Fabrication

Automated multidirectional UV exposure has been demonstrated using a collimated UV source and a movable stage equipped with two computer controlled motors and a microcontroller for complex three dimensional (3-D) microstructures. The stage is tilted and rotated using independently controlled motors by user’s programming during UV exposure. Various dynamic operations with the angular velocities of tilting and rotation harmonically related have been exercised using a SU-8 coated substrate and the reverse-side exposure scheme. Implemented structures using the dynamic mode include a vertical reverse triangular slab, a quadruple reverse triangular slab, a cardiac horn, screwed wind vane shapes with two blades and four blades. Ray tracing simulation using mathematical equations has been performed to confirm the shapes of resultant structures.

(Left) Schematic of the 3D multidirectional lithography setup and operation. (Right) SEM of an example structure: screwed wind vanes with four blades.