Regular ultrasound probes have flat bases, which means they only work best when scanning objects that have similarly-flat surfaces. So, what happens if you want to inspect something that’s curved or otherwise “irregular” in shape? Well, that’s where a new ultrasound patch comes in.
Designed by a team at the University of California San Diego’s Jacobs School of Engineering, the stretchable, flexible patch consists of a thin silicone elastomer sheet with an embedded “island-bridge” electronic structure. The islands in that structure are an array of electrodes and piezoelectric transducers, while the bridges linking them together are spring-shaped copper wires.
The patch can be placed on any object with a non-flat surface – or in a hard-to-reach area that a conventional probe can’t get into – with no gel or other contact-enhancing solution required. When an electrical current is subsequently run through the patch, the piezoelectric transducers produce ultrasound waves that allow the inner structure of the object to be visualized.
It has already been tested on an aluminum block, successfully imaging 2-mm-wide holes and cracks located 2 to 6 centimeters (0.8 to 2.4 inches) beneath the block’s wavy surface.
Ultimately, it is hoped that the technology could be used to inspect items such as engine parts, turbines, reactor pipe elbows and railroad tracks. It’s still in the proof-of-concept stage for the time being, and needs to be hooked up to a computer along with an external power source – but that could change.
“In the future, we hope to integrate both power and a data processing function into the soft ultrasound probe to enable wireless, real-time imaging and videoing,” says Prof. Sheng Xu, corresponding author of a paper on the study.