Release of moving silicon microstructures embedded in a bonded multi-wafer stack using DRIE

We present a method to release temporarily anchored, moving microstructures, embedded in a bonded multiple-wafer stack, using standard DRIE for the removal of sacrificial silicon support beams. This technique enables the batch fabrication of complex MEMS structures that include several levels of gears, bearing structures, and other moving parts. Such designs have broad applications in microrobotics, medical devices, and power harvesting. The described method is applied to create a functional rotary silicon micro-ball bearing with integrated dual-row ball cage.