Micromachined high frequency PMN-PT/epoxy 1-3 composite ultrasonic annular array

Area of Science:

• Materials Science
• Mechanical Engineering
• Electrical Engineering

Background:

• Miniature high-frequency ultrasonic transducers are crucial for advanced imaging and sensing.
• Fabricating high-density piezoelectric arrays with fine features presents significant challenges.

Purpose of the Study:

• To report the design, fabrication, and performance of micromachined PMN-PT/epoxy 1-3 composite ultrasonic annular arrays.
• To demonstrate a novel electrical interconnection strategy for high-density array elements.

Main Methods:

• Utilized micromachining techniques to create PMN-PT single crystal 1-3 composites with 9x9 μm pillars and ~5 μm kerfs.
• Fabricated a six-element annular transducer with 0.2 mm² element area and 16 μm kerf widths, featuring a 1.5 mm diameter aperture.
• Implemented a novel electrical interconnection strategy for high-density array elements.

Main Results:

• Achieved a center frequency of 50 MHz with a -6 dB bandwidth of 90%.
• Measured an average two-way insertion loss of 19.5 dB at 50 MHz.
• Observed crosstalk between adjacent elements of approximately -35 dB.

Conclusions:

• The developed micromachining techniques are promising for fabricating various high-frequency transducers, including 1D and 2D arrays.
• The performance metrics demonstrate the viability of these miniature arrays for high-frequency ultrasonic applications.