Experimental Investigation of Inter-element Isolation in a Medical Array Transducer at Various Manufacturing Stages

Area of Science:

• Materials Science
• Acoustics
• Transducer Technology

Background:

• Cross-coupling in fabricated prototypes is well-researched.
• Few studies investigate cross-coupling in transducer arrays at various manufacturing stages.

Purpose of the Study:

• To experimentally investigate vibration maps of a linear array transducer during manufacturing.
• To analyze the impact of manufacturing steps on cross-coupling and inter-element isolation.

Main Methods:

• Utilized a laser Doppler vibrometer to measure vibrations of a 192-element linear array transducer.
• Tested the array in air and water at various finishing stages, driving only the central element at 5 MHz.

Main Results:

• Cross-coupling contributions are influenced by acoustic stack components (PZT, kerf, filler, matching layer, lens).
• Inter-element isolation varied from -22 dB in air (after kerf cutting) to -2 dB in water (with a full acoustic stack).
• Vibration patterns in water exhibited higher standard deviation (up to 30%) due to acousto-optic interactions.

Conclusions:

• The manufacturing process significantly affects transducer array performance and cross-coupling.
• Acoustic stack composition and environmental conditions (air vs. water) influence vibration characteristics.
• This method aids manufacturers in correlating production steps with quantitative performance evaluations.