Microbricks for Three-Dimensional Reconfigurable Modular Microsystems

This paper explores the design of “microbricks”-interlocking microscale building blocks that can be used to assemble and reconfigure 3-D structures on a regular lattice. We present the design and fabrication of a space-filling rotation and flip-invariant 500-μm microbrick architecture suitable for 3-D assembly. We describe the design considerations used to optimize mechanical, fabrication, and assembly properties of the components and the finished structures. The final brick geometry was fabricated using two different fabrication techniques: Silicon bricks were micromachined out of silicon, and SU-8 polymer tiles were built up in a three-layer process. The resulting bricks were characterized, and proof-of-concept structures comprising ten bricks were assembled to demonstrate the physical interlocking and compatibility between the two materials. We suggest that the presented interlocking geometry could serve in the future to fabricate passive and active modular macroscale structures from microscale components.