Development of 20 MHz linear array transducer for small animals imaging based on dual sub-element structure

Area of Science:

• Biomedical Engineering
• Acoustic Imaging
• Materials Science

Background:

• High-frequency array transducers face limitations in penetration depth due to weak transmitting energy.
• Overwide apertures in these transducers cause significant sidelobe effects, degrading image quality.

Purpose of the Study:

• To propose a design strategy for high-frequency array transducers that enhances penetration depth and suppresses sidelobe effects.
• To optimize transducer structure parameters using finite element modeling for improved acoustic energy transmission.

Main Methods:

• Utilized finite element modeling (FEM) to analyze the impact of sub-element kerf on transducer performance.
• Designed and fabricated a 128-element, 20 MHz linear array transducer based on optimized parameters.
• Conducted experimental evaluations of bandwidth, resolution, and imaging depth.

Main Results:

• Achieved a -6 dB bandwidth of 48% and lateral/axial resolutions better than 250 μm and 100 μm, respectively.
• Demonstrated an imaging depth exceeding 5 cm, surpassing conventional limitations.
• Successfully performed real-time high-frequency ultrasound imaging in small animals, including cardiac and vascular imaging.

Conclusions:

• The proposed dual sub-element design strategy effectively enhances the performance of high-frequency linear array transducers.
• This approach offers a feasible pathway for improving acoustic energy transmission and imaging capabilities.
• The developed transducer shows significant potential for advanced small animal imaging applications.