Effect of triangular pillar geometry on high- frequency piezocomposite transducers

Area of Science:

• Materials Science
• Biomedical Engineering
• Acoustics

Background:

• Piezocomposite materials are crucial for biomedical transducer arrays.
• High-frequency imaging demands piezocomposites that minimize lateral resonances, a challenge with traditional square pillar designs.
• Triangular pillars offer a potential solution to suppress these resonances.

Purpose of the Study:

• To investigate the impact of triangular pillar geometry on lateral resonances in piezocomposite materials.
• To determine the optimal triangular pillar angle for high-frequency biomedical transducer applications.
• To validate simulation findings through experimental fabrication and testing.

Main Methods:

• Finite-element analysis was used to simulate piezocomposite transducers with varying isosceles triangular pillar angles (30-60 degrees).
• Simulations considered different pitch, kerf width, and thickness parameters to assess optimal angles under various conditions.
• Experimental fabrication using a dice-and-fill technique and acoustical/electrical measurements were performed to validate simulations.

Main Results:

• Simulations revealed that triangular pillars with a 45-degree angle exhibit the lowest secondary pulse amplitude, minimizing lateral resonances.
• Deviations from the 45-degree angle increased secondary pulse amplitude, indicating reduced performance.
• Experimental measurements of electrical impedance and pulse response confirmed the simulation findings, validating the 45-degree design's optimal performance.

Conclusions:

• The 45-degree triangular pillar geometry is the optimal configuration for high-frequency piezocomposite transducer applications among all investigated designs.
• This optimized geometry effectively suppresses lateral resonances, leading to improved transducer performance.
• Experimental validation confirms the theoretical predictions and the superiority of the 45-degree triangular pillar design.