Air-Coupled Ultrasonic Ferroelectret Receiver with Additional DC Voltage

Proceedings

Gaal, Mate¹ 

关键词: ultrasonic;    air-coupled;    cellular polypropylene;    transducer;    ferroelectret;   

DOI  :  10.3390/proceedings1040362

学科分类：社会科学、人文和艺术（综合）

来源: mdpi

【 摘 要 】

Highly sensitive air-coupled ultrasonic sensors are essential for various applications such as testing of composite materials. One of the major challenges for the development of air-coupled ultrasonic sensors is the impedance matching to air. With a lower acoustic impedance than the usual piezoelectric materials, charged cellular polypropylene film (cPP) offers better matching to air with a similar piezoelectric coefficient. The piezoelectric behaviour demonstrated by cPP comes from polarized air cells that create a permanent internal voltage. The sensitivity of the sensor varies with the application of an additional DC bias voltage. Thus, this work presents a cPP ultrasonic sensor with an improvement of up to 15 ± 1 dB on the signal-to-noise ratio.

【 授权许可】

CC BY