Inexpensive Acoustoelectric Hydrophone For Mapping High Intensity Ultrasonic Fields

Area of Science:

• Acoustics
• Materials Science
• Electrical Engineering

Background:

• Conventional hydrophones for ultrasonic field measurement can be expensive.
• The acoustoelectric (AE) effect describes the interaction between electrical current and pressure.

Purpose of the Study:

• To describe an inexpensive alternative to conventional hydrophones for measuring ultrasonic fields.
• To evaluate the performance of a novel AE hydrophone.

Main Methods:

• Constructed a hydrophone using common laboratory supplies based on the acoustoelectric effect.
• Measured beam patterns of a 540 kHz annular transducer using the AE hydrophone.
• Compared the results with those obtained using conventional hydrophones.

Main Results:

• The AE hydrophone beam patterns were consistent with conventional hydrophone measurements.
• The AE signal showed proportionality to applied bias current (1.83 µV/mA) and pressure (13.3 µV/MPa).
• Achieved a sensitivity better than 50 kPa.

Conclusions:

• The developed graphite hydrophone offers an inexpensive and effective method for measuring ultrasonic fields.
• Disposable AE hydrophones present an attractive option for clinical applications requiring monitoring of high-intensity acoustic fields.