Abstract
A novel micromachined accelerometer based on micro thermal-bubble technology is proposed and demonstrated in this dissertation. Unlike the other techniques, the only moving element in this accelerometer is a small thermal-bubble created by using a high flux heater to vaporize the liquid contained in the micro chamber. The accelerometer consists mainly of a heating resistor, which creates a symmetrical temperature profile, and several pairs of temperature sensors placed symmetrically on either side of the heater. The bubble technology is employed due to the clear interface between thermal-bubble and working liquid, providing good thermal conduction and high density. The basic physical characteristics including the heat transfer and fluid flow behavior of this accelerometer have been analyzed and discussed in this work. The feasibility and performance of the proposed accelerometer are verified using numerical simulations and demonstrated experimentally using a designed test setup. The prototype devices indicate that a sensitivity of 200 mV/g for an operating power of 60 mW can be realized. The frequency response containing DI water is measured to be 200 Hz, and the corresponding noise equivalent acceleration is approximately 1 mg/Hz1/2. The results conclude that the presented design has better response and higher sensitivity comparing to its counterparts.