Capacitive Micromachined Ultrasonic Transducers (CMUTs) for Underwater Imaging Applications

Sensors

Jinlong Song¹  Chenyang Xue¹  Changde He¹  Rui Zhang¹  Linfeng Mu¹  Juan Cui¹  Jing Miao¹  Yuan Liu¹  Wendong Zhang¹ 

[1] Key Laboratory of Instrumentation Science & Dynamic Measurement, Ministry of Education, North University of China, Taiyuan 030051, China; E-Mails:

关键词: CMUT;    C-V characteristic curve;    sound pressure;    bandwidth;    ultrasonic imaging;   

DOI  :  10.3390/s150923205

来源: mdpi

【 摘 要 】

A capacitive micromachined ultrasonic transducer structure for use in underwater imaging is designed, fabricated and tested in this paper. In this structure, a silicon dioxide insulation layer is inserted between the top electrodes and the vibration membrane to prevent ohmic contact. The capacitance-voltage (C-V) characteristic curve shows that the transducer offers suitable levels of hysteresis and repeatability performance. The −6 dB center frequency is 540 kHz and the transducer has a bandwidth of 840 kHz for a relative bandwidth of 155%. Underwater pressure of 143.43 Pa is achieved 1 m away from the capacitive micromachined ultrasonic transducer under 20excitation. Two-dimensional underwater ultrasonic imaging, which is able to prove that a rectangular object is present underwater, is achieved. The results presented here indicate that our work will be highly beneficial for the establishment of an underwater ultrasonic imaging system.

【 授权许可】

CC BY   
© 2015 by the authors; licensee MDPI, Basel, Switzerland.