Piezoelectric transducer design for a miniaturized injectable acoustic transmitter. (7th October 2015)

• Record Type: Journal Article
• Authors: Li, H; Jung, K W; Deng, Z D
• Is Part Of: Smart materials and structures. Volume 24:Number 11(2015:Nov.)
• Publication Date: 2015-10-07
• Subjects: acoustic transducer -- piezoelectric -- PZT -- underwater acoustic transmitter -- fish tag -- source level -- beam pattern; 43.38.+n and 43.38.-p; Smart materials -- Periodicals; Strucural design -- Periodicals; 620.11
• DOI: 10.1088/0964-1726/24/11/115010
• Languages: English
• ISSNs: 0964-1726

Abstract

Abstract: Implantable acoustic transmitters have been used in the last 20 years to track fish movement for fish survival and migration behavior studies. However, the relatively large weights and sizes of commercial transmitters limit the populations of studied fish. The surgical implantation procedures may also affect fish adversely and incur a significant amount of labor. Therefore, a smaller, lighter, and injectable transmitter was needed, and similar or better acoustic performance and service life over those provided by existing commercial transmitters was desired. To develop such a small transmitter, a number of technical challenges, including design optimization of the piezoelectric transducer, needed to be overcome. Our efforts to optimize the transducer focused on improving the average source level in the 180° range in which the signal was not blocked by the transmitter body. We found that a novel off-center tube transducer improved the average source level by 1.5 dB. An acoustic reflector attached to the back of the transducer also improved the source level by 1.3 dB. We found that too small a gap between the transducer and the component placed behind it resulted in distortion of the beam pattern. Lastly, a tuning inductor in series with the transducer was used to help optimize the source level. The findings and techniques developed in this work contributed to the successful development and implementation of a new injectable transmitter.