熱氣泡式微型加速度計之設計、製造與測試

近幾年來微加速度計被廣泛的運用於許多領域中，包括：車輛工業、消費性電子產品、導航系統、軍事及機器手臂等。然而，在應用方面，目前微加速度計的性能仍有改善的空間。本文提出一熱氣泡式微加速度計，其具有無質量塊、頻率響應快、體積小、靈敏度高等優點，此新的感測機制係利用一高熱通量的加熱器於密閉的流體環境中加熱以產生熱氣泡，藉由量測流場內，因外加慣性力產生的溫度變化情形，感測出此加速度的大小及方向。本文針對此加速度計的基本物理特性進行分析，並利用數值方法觀察流場內流體的熱傳與流動的行為，闡明在微觀尺度下兩相流的運動機制，藉以獲得加速度與溫度分佈的關係，進而評估此加速度計的性能。本研究利用微加工的方式成功製作出加速度計原型，並利用所建構實驗平台量測加速度計之靜態與動態特性，探討此加速度計於不同元件尺寸與操作條件下，對其性能所造成的影響。同時，針對此加速度計的穩定度、雜訊、解析度、靈敏度等做深入的研討。本文希望能為加速度計於將來微機電技術的應用中，提出新的設計概念。

關鍵字

微加速度計；熱氣泡；熱毛細對流

並列摘要

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.

並列關鍵字

Micromachined accelerometer ； Thermal-bubble ； Thermocapillary convection

國際替代計量

熱氣泡式微型加速度計之設計、製造與測試

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