A Low Frequency Broadband Flextensional Ultrasonic Transducer Array.

Area of Science:

• Acoustics and Materials Science
• Ultrasonic Transducer Technology

Background:

• Flextensional transducers are crucial for low-frequency ultrasonic applications.
• Optimizing transducer design for wideband, high-sensitivity operation remains a key challenge.

Purpose of the Study:

• To design and fabricate a multicell, piezoelectrically actuated flextensional transducer array.
• To achieve low mechanical impedance for wideband and high-sensitivity immersion operation in the low ultrasonic frequency range (30-100 kHz).

Main Methods:

• Utilized finite element modeling (FEM) to investigate material influences on electroacoustic behavior.
• Optimized transducer components and cell layout for an 80-mm diameter active area.
• Fabricated the transducer using PZT-5H ceramic disks, stainless steel, FR-4 laminates, and brass, with epoxy resin and wire bonding for assembly.

Main Results:

• Developed a transducer with 121 cells (6 mm diameter each) forming a quasi-circular active area.
• Achieved a total transducer thickness of less than 10 mm.
• Characterized electrical impedance and transmit pressure field, demonstrating suitability for target applications.

Conclusions:

• The proposed flextensional transducer array design offers a flexible and effective solution for broadband, high-sensitivity low-frequency ultrasonic applications.
• The fabrication process ensures accurate assembly and reliable performance.
• The study provides valuable insights into material selection and geometric optimization for flextensional transducer design.