表面聲波感測器之量測系統建立及其應用

Building of Measurement System for Surface Acoustic Wave Sensors and Its Applications

林琦軒(Rek Lin)

指導教授 ： 施文欽

大同大學/電機資訊學院/光電工程研究所/碩士(2004年)

摘要

現今的壓電振盪器已被廣泛地應用在質量、溫度和有機氣體的感測與生醫工程等各種領域中。如石英晶體微天平被運用在感測質量的微量變化，利用鈮酸鋰晶體製作的表面聲波元件被運用在感測溫度的微量變化。表面聲波元件其表面上所塗佈選擇性的聚合薄膜可作為化學感測器，並運用在感測不同有機氣體。
在本論文中，我們首先建立了一簡單且高靈敏度的表面聲波感測器量測平台。此量測平台利用表面聲波振盪器來產生一高頻振盪頻率，其中包括了表面聲波延遲線元件，匹配電路，射頻積體電路，低通濾波器，最後經由頻率計數器，得到一穩定輸出頻率，再經通用介面匯流排將數值傳回電腦做分析，而此感測器量測平台的穩定度經過測試小於 3.5 ppm。
在本論文實驗中，我們利用自製和商業的表面聲波元件做為一物理感測器，對質量和溫度來做感測，而在實驗中所感測出之結果將在本文中作相關的研究與討論。未來計畫將此平台結合生物醫學，做為一生物感測器，做微量病毒的感測或有毒生化氣體的偵測。

關鍵字

表面聲波感測器，質量加載

並列摘要

Piezoelectric oscillators have been widely used as sensors for mass, temperature, organic gas, bio-medical engineering and many other fields. For example, quartz crystal microbalance (QCM) has been the most extensively used in mass sensing devices. Surface acoustic wave (SAW) devices coated with selective polymer as chemical sensors become popular in the detection of a variety of organic gases.
In lots of researches, we know that the sensitivity of the oscillating circuit based on SAW delay line is better than that based on QCM because SAW device has higher operating frequency compared to QCM device. In this thesis, a highly sensitive and easily assembled SAW sensor measurement platform is built up. This platform configured as a SAW oscillator consists of SAW delay line, impedance matching network, RFIC amplifier, and a low pass filter. This stable output frequency has been measured by frequency counter and transported to computer through general-purpose interface bus (GPIB). The stability of this platform has been measured as a frequency changes less than 3.5 ppm.
In this thesis, this platform has been used for mass and temperature sensing. Results were obtained and discussed with commercial and homemade SAW devices. This platform has been shown to be potential for bio-medical engineering applications in the future.

並列關鍵字

mass loading ； surface acoustic wave sensor

參考文獻

[2] C. K. Campbell, “Surface Acoustic Wave Devices for Mobile and Wireless Communications,” 1998

[4] D. S. Ballantine, R.M. White, “Acoustic Wave Sensors-Theory, Design, and Physic-Chemical Applications”, 1997

[5] H. Wohltjen, “Surface acoustic wave microsensors,” in Proc. 4th Int. Solid-State Sens. Actuators Conf., 1987, pp.471-477

[6] C. Wold et al., “Temperature measurement using surface skimming bulk waves,” in Proc. Ultrason. Symp, Vol. 1, 1999, pp. 441-444

[7] F. Schmidt, G. Scholl, “Wireless SAW Identification and sensor systems,” Int. Journal of High Speed Electronic and systems, Vol. 10, No. 4, pp.1143-1191, 2000