Micromachined polycrystalline diamond hemispherical shell resonators

Abstract

We present the development of millimeter scale 3D hemispherical shell resonators fabricated from polycrystalline diamond, a material with low thermoelastic damping and very high stiffness. Resonators are fabricated through a combination of electro discharge machining (EDM) and silicon micromachining techniques, to achieve 1 mm diameter 3D highly axisymmetric hemispherical shell structures. By using piezoelectric actuation and optical characterization, the elliptical wineglass vibration mode is determined to be at 34.86 kHz, with the two degenerate wineglass modes having a relative frequency mismatch of 2%.