表面聲波傳感器之研製

Design of Surface Acoustic Wave Transducer

宋愈貴(Yu-Kuei Sung)

指導教授 ： 丁鏞

中原大學/工學院/機械工程研究所/碩士(2020年)

https://doi.org/10.6840/cycu202000909

摘要

本論文的研究目標為設計一具有高靈敏度、設計靈活度高且製作容易等優勢之表面聲波傳感器，可應用於非破壞性檢測領域上作檢測使用。主要是設計傳感器能以蘭姆波的波動形式發射與接收聲波，並用MATLAB繪製頻散曲線圖有助於分析設計頻率的使用模態。本研究使用的壓電材料為PZT-4，其具有較好的d33與g33值，能夠有較穩定的電壓輸出與接收。另外在傳感器製作上是採用表面極化的方式做極化，有別於一般表面聲波元件使用厚度極化的方法，會有較高的輸出較果與較高的靈敏度。通過實驗施加20Vpp電壓與頻率於1.78MHz，後驗證表面極化的3.9Vpp高於厚度極化的2.1Vpp電壓值。並進行非破壞性檢測的模擬實驗，施加20Vpp的電壓後，經過發射與接收兩傳感器間之待檢測物的裂痕，在儀器上可觀測出當蘭姆波經過裂痕處後從0.86Vpp衰減至0.36Vpp，可驗證元件可運用在非破壞性檢測上。另外改用PVDF高分子複合材料做表面聲波元件，通過實驗驗證PVDF在20Vpp電壓與頻率於1.56MHz驅動條件下，PVDF的表面極化結果為4.3Vpp，並且高於PZT的表面極化結果3.9 Vpp，以此證明PVDF比PZT有較好的靈敏度。

關鍵字

壓電陶瓷PZT ； PVDF高分子複合材料 ； 表面聲波傳感器 ； 非破壞性檢測

並列摘要

The research objective of this paper is to design a high-sensitivity, high-flexibility and easy-manufacture surface acoustic transducer applied for the non-destructive testing. The main design of transduce is able to generate and receive signals of Lamb wave. By means of MATLAB, the dispersion curve can help analyze the use mode of the design frequency. The piezoelectric material used in this paper is PZT-4, which has good d33 and g33 values and a more stable voltage output and reception. In addition, surface polarization is used for transducer fabrication, which is different from the thickness polarization method for most of surface acoustic wave components. It has higher output and higher sensitivity. In experiment, applying a voltage of 20 Vpp and a frequency of 1.78 MHz, it was found that the surface polarization of 3.9 Vpp was higher than the thickness of 2.1 Vpp. While applying a voltage of 20Vpp, after passing through the crack in the middle of the detection area, it can be observed that the Lamb wave decays from 0.86Vpp to 0.36Vpp. Such a transducer and detection system are verified can be used for non-destructive testing. In addition, the PVDF polymer composite material is designed as the surface acoustic wave device and compared with the PZT transducer. It was experimentally verified that the PVDF had a surface polarization result of 4.3 Vpp at a voltage of 20 Vpp and a frequency of 1.56 MHz. This proves that PVDF has better sensitivity than PZT.

並列關鍵字

Piezoceramic PZT ； PVDF polymer composite ； Surface acoustic wave transducer ； Non-destructive detection

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