Wireless, RF & Smart Dust

As RF MEMS technology evolves to shift towards UHF frequencies, the parasitics inherent in hybrid fabrication approaches become the performance bottleneck. This project aims to integrate metal MEMS resonators directly over CMOS circuitry to achieve fully integrated MEMS systems. Pursuant to this goal, this project proposes several designs for UHF MEMS bandpass filters, exploring how different CMOS-compatible metals can yield performance metrics—such as quality-factor (Q), temperature stability and frequency drift—that are comparable to those of standard polysilicon MEMS resonators....

A self-healing MEMS RF switch, which utilizes liquid gallium contacts to take the place of the traditional metal-to-metal hard contacts, is proposed in this project. Electrostatic actuation is used to drive a silicon nitride diaphragm with upper electrodes. When the diaphragm is pulled down by the electrostatic force, small droplets of liquid gallium work as an interface between the upper and lower electrodes. The loss of the gallium droplets can be avoided due to the unwettability of the material surrounding the contact areas. In this project, hermit package and 1A DC current...

The objective of this project is to develop micro-electromechanical tunable capacitors employing dielectric fluids. In the case of electrostatic, mechanically tunable capacitors the goal is to increase the capacitance per unit area and the tuning range, reduce the mechanical noise and also improve mechanical performance and long-term reliability.

Project end date: 08/18/04

Our group previously demonstrated a “neural dust” system for neural recording which includes an implantable device and external ultrasonic transducers to power and communicate with the implantable. In this work, we extend that paradigm, demonstrating an implantable that can measure and report tissue oxygenation. Oxygenation state is a key parameter when assessing the metabolic state of cells and tissues, tissue and organ viability, tumor state, among many examples in both basic science and clinical care. Various types of methods for the detection of oxygen have appeared in recent...