Development of a capacitive ultrasonic sensor having parylene diaphragm and characterization of receiving performance of arrayed device
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- 作者：Seiji Aoyagi ; Katsuhide Furukawa ; Daisuke Ono ; Kaoru Ymashita ; Tsunehisa Tanaka ; Koji Inoue ; Masanori Okuyama
- 关键词：Parylene ; Ultrasonic sensor ; Capacitive sensor ; Ranging system ; Arrayed sensor ; Electric scanning of directivity
- 刊名：Sensors and Actuators A: Physical
- 出版年：2008
- 出版时间：July-August 2008
- 年：2008
- 卷：145-146
- 期：Complete
- 页码：94-102
- 全文大小：1829 K
文摘
The present paper reports the development of a capacitive ultrasonic sensor having Parylene diaphragm. Parylene diaphragm is flexible and non-brittle, allowing good sensitivity and durability. The resonant frequency under the tensile stress of Parylene and the influence of the number and the radius of acoustic holes on damping ratio are investigated by FEM (finite element method) simulation. Practical sensor devices are fabricated. They can receive an impulsive ultrasonic pulse transmitted by a spark discharge. The ranging system using this sensor can detect the distance up to 1 m with the error less than 1 mm. The developed sensor can be approximated to be non-directional. An arrayed sensor device comprising 5 × 5 developed sensors is fabricated, and its receiving performance is characterized. It is proven that the electric scanning of directivity based on delay-and-sum principle is possible.