Surface micromachined capacitive ultrasonic transducers

Area of Science:

• Materials Science
• Acoustics
• Engineering

Background:

• Surface microfabrication techniques have advanced.
• Ultrasonic transducers are crucial for various sensing and imaging applications.
• Existing piezoelectric transducers have limitations in certain environments.

Purpose of the Study:

• To report on the current state of surface microfabricated ultrasonic transducer technology.
• To demonstrate the performance of these transducers in air and water.
• To compare their potential against piezoelectric transducers.

Main Methods:

• Experimental testing of microfabricated ultrasonic transducers for air and water transmission.
• Measurement of dynamic range in air-coupled longitudinal wave transmission through aluminum.
• Evaluation of signal-to-noise ratio (SNR) in water transmission experiments.
• Development and validation of a theoretical model for transducer behavior.

Main Results:

• Demonstrated air-coupled longitudinal wave transmission through aluminum with a 110 dB dynamic range at 2.3 MHz.
• Achieved a 60 dB SNR at 3 MHz during water transmission experiments (1-20 MHz).
• A theoretical model accurately predicted observed transducer performance.

Conclusions:

• Microfabricated ultrasonic transducers exhibit excellent performance in both air and water.
• These transducers present a compelling alternative to conventional piezoelectric transducers.
• The developed theoretical model supports the viability of this novel technology.