Liwei Lin (Advisor)

Cavity Optomechanical oscillators (OMOs) rely on photon radiation pressure to induce harmonic mechanical motion of a micron-scale light resonator. Unlike most oscillators, optomechanical oscillators require only CW input light without the need for electronic feedback and so hold promise for their novelty. In an optical cavity of sufficient quality factor, the transduction from photons to phonons can be quite efficient as we characterized optomechanical cavities which only required 17 microwatt input optical power to induce mechanical oscillation. The question then remains whether OMOs can...

On chip capacitive-gap transduced micromechanical resonators constructed via MEMS technology have achieved very high Q’s at both VHF and UHF range, making them very attractive as on-chip frequency selecting elements for filters in wireless communication applications. Still, there are applications, such as software-defined cognitive radio, that demand even higher Q’s at RF to enable low-loss selection of single channels (rather than bands of them) to reduce the power consumption of succeeding electronic stages down to levels more appropriate for battery-powered handhelds. This...

Ultrasound has long been used for medical imaging. Recent advances of miniaturized MEMS ultrasonic transducers new applications such as gesture recognition, personal fitness devices, and fingerprint sensors. These devices are considerably smaller than conventional transducers. To benefit from their lower excitation power requirements and address the reduced sensitivity requires the design of novel interface electronic circuits.

The first part of this thesis describes new circuits capable of generating all the high voltage drive signals for MEMS transducers on-chip from a single low...