Versatile and scalable fabrication method for laser-generated focused ultrasound transducers

Area of Science:

• Materials Science
• Acoustic Engineering
• Biomedical Engineering

Background:

• Focused ultrasound transducers are crucial for various medical and industrial applications.
• Existing fabrication methods can be complex and lack scalability.
• The need for versatile and cost-effective transducer fabrication is growing.

Purpose of the Study:

• To propose a versatile and scalable fabrication method for laser-generated focused ultrasound transducers.
• To demonstrate the incorporation of different optical absorbers into the transducers.
• To characterize the performance of the fabricated transducers.

Main Methods:

• A stamping technique using a coated negative mold onto polydimethylsiloxane (PDMS) was employed.
• Optical absorbers, including multiwalled carbon nanoparticles, candle soot nanoparticles, and gold nanoparticles, were integrated.
• Transducers of varying sizes (down to 3 mm diameter) were fabricated and tested.

Main Results:

• Fabricated transducers operated at central frequencies around 10 MHz with bandwidths of 15-20 MHz.
• A 5 mm diameter transducer generated over 35 MPa peak pressure with a 150 μm focal spot.
• Ultrasound cavitation was successfully demonstrated using a 3 mm diameter transducer.

Conclusions:

• The proposed method offers a versatile and scalable approach for fabricating focused ultrasound transducers.
• The integration of various optical absorbers allows for tailored transducer properties.
• The demonstrated performance, including high peak pressure and cavitation induction, highlights the potential of these transducers.