A cover article in The Journal of Applied Physics describes how a team of researchers at Penn State Materials Research Institute designed and computationally tested a device constructed of a manmade metamaterial that can manipulate a variety of sound waves. Expected to benefit almost all current sonic and ultrasonic applications, the invention could lead to more accurate and efficient high intensity focused ultrasound therapies.
Built on gradient-index phononic crystals — an array of steel pins embedded in epoxy in a particular pattern – the new device can shrink or expand the aperture of an acoustic beam with minimum energy loss and waveform distortion. Researchers believe the lens will eliminate the need and expense of having transducers of different sizes on hand for research and surgical use.
Sz-Chin Steven Lin, PhD, a postdoctoral scholar at Penn State, is lead author of the paper. Co-authors are Bernhard R. Tittmann, PhD and Tony Jun Huang, PhD.