A Korean research team has presented a standard protocol for fabricating a "transparent ultrasound transducer (TUT)" that simultaneously transmits light and sound (ultrasound) along the same path. The development is seen as raising the prospect of next-generation medical devices that can examine the inside of the body in real time using just a single device placed on the skin.
A research team led by Professor Kim Chul-hong at POSTECH's Department of Electrical Engineering, Department of Convergence IT Engineering, Department of Mechanical Engineering, and Graduate School of Convergence Science and Technology, together with a team led by Professor Park Jeong-woo at Kyungpook National University, announced Wednesday that they have systematized the technology for developing a transparent ultrasound transducer that precisely integrates light and ultrasound into a single path. The findings were published on the 8th (local time) in the international academic journal Nature Protocols.
A transducer is a device that converts the form of energy, such as transforming electrical signals into ultrasound and then back into image signals. The transducer is also the core component of ultrasound examination equipment used in hospitals.
In particular, research combining ultrasound and optical technologies has been active recently in the biomedical field. Ultrasound can see deep into the body, while light is strong in clearly observing fine structures such as cells and blood vessels, so using the two technologies together enables more precise diagnosis and treatment.
However, conventional ultrasound transducers had the problem of being opaque and unable to transmit light. As a result, optical devices and ultrasound sensors had to be placed separately, leading to limitations such as bulky equipment and reduced image alignment accuracy. This served as a major constraint particularly in the development of wearable devices and ultra-compact endoscopes.
The transparent ultrasound transducer developed by the research team can deliver light and ultrasound simultaneously along a single axis. Whereas cameras and ultrasound sensors were previously arranged at offset, oblique angles, the same location can now be observed simultaneously through a single transparent device.
The research team went beyond technology development to publicly release a standard fabrication protocol. The protocol organizes the entire process step by step, from material selection to design, electrode fabrication, and performance verification, and is structured so that researchers with related experience can complete fabrication and verification within about three weeks.
The team expects the technology to be utilized in wearable healthcare devices, ultra-compact endoscopes, and real-time image-guided treatment systems. It is also expected to contribute to the advancement of precision medicine fields that simultaneously use light and ultrasound, including cancer diagnosis and treatment, vascular monitoring, and biosignal analysis.
"We have lowered the entry barrier to developing multi-mode biomedical systems that align and utilize optics and ultrasound on a single axis," Professor Kim said, explaining the significance of the research. Professor Park added, "Researchers can now systematically design, fabricate, and verify the performance of transparent ultrasound transducers tailored to their application purposes, which we expect will contribute to the development of various bio-imaging and therapeutic convergence technologies in the future."
