Shell Resonators

Miniature resonators are required for a range of applications, including signal processing, timing, frequency control, and inertial sensing. A wide array of surface and bulk fabrication technologies for silicon MEMS resonators has been developed over the past decades with several commercial silicon resonators currently entering the consumer electronics market. Conventional planar technologies for MEMS resonator fabrication rely on photolithography and silicon DRIE which provide relative fabrication tolerances on the order of 1%. The fabrication imperfections, surface roughness, DRIE induced scalloping and footing, as well as aspect ratio limitations present challenges in device symmetry, frequency specification and matching, quality factor maximization, and further device miniaturization without performance sacrifice. These factors motivate the investigation of alternative, non-planar architectures and technologies for resonant MEMS with simultaneously increased symmetry and aspect ratios.

This project utilizes a new paradigm for design and fabrication of 3-D spherical shell resonators. The approach uses pressure and surface tension driven plastic deformation (glassblowing) on a wafer scale as a mechanism for the creation of inherently smooth and symmetric 3-D resonant structures with integrated electrodes. Integrated 3-D metal electrodes can be used to actuate the two dynamically balanced 4-node wineglass modes. The intrinsic manufacturing symmetry and high aspect ratio transducer architectures of the proposed technology may enable new classes of high performance 3-D MEMS for communications and navigation applications.