Researchers at Washington University in St. Louis recently invented a technique for generating ultrasound waves that can self-bend, like a rainbow.
Airy beams (named for English scientist George Biddell Airy) are a class of acoustic waves that move on a curved, arch-like trajectory and can auto-focus around obstacles that are directly in the beams’ path, which makes them well suited for ultrasound applications in biomedical imaging, therapy, nondestructive testing and particle manipulation. However, generating Airy beams in water requires large, expensive equipment, which has limited their broad applications in ultrasound.
Hong Chen, associate professor of biomedical engineering at the McKelvey School of Engineering and of radiation oncology at the School of Medicine, and members of her laboratory designed and 3D-printed a flexible and versatile tool known as Airy beam-enabled binary acoustic metasurfaces (AB-BAMs) for ultrasound beam manipulation. They then demonstrated the capability of AB-BAM in water.
They reported their findings recently in Physical Review Applied.