题 目：Asymmetric sound transmission via acoustic metasurfaces
时 间：6月8日（周四 ），下午4:00-5:00
In this talk, I will present our recent works on asymmetrical sound transmission using acoustic metasurfaces. In the first work, the design consists of a layer of gradient-index metasurface and a layer of low refractive index metasurface. Incident waves are controlled in a wave vector dependent manner to create strong asymmetric transmission. Numerical simulations show that the approach provides high transmission contrast between the two incident directions within the designed frequency band. This is further verified by experiments. In the second work, we show that robust and tunable acoustic asymmetric transmission can be achieved through a single gradient-index metasurface by harnessing judiciously tailored losses. We theoretically prove that the asymmetric wave behavior stems from loss-induced suppression of high order diffraction. We further experimentally demonstrate this novel phenomenon. Our findings could provide new routes to broaden applications for lossy acoustic metamaterials and metasurfaces.
Yun Jing received a B.S. degree in electronic science and engineering from Nanjing University, China, in 2006 and an M.S. degree from Rensselaer Polytechnic Institute in 2007. He received his Ph.D. degree in architectural acoustics from Rensselaer Polytechnic Institute in 2009. Prior to joining the NC State faculty as an assistant professor in 2011, he was a research fellow at Brigham and Women's Hospital, Harvard Medical School. He was promoted to Associate Professor in 2017. He specializes in biomedical ultrasound, acoustic metamaterials, architectural acoustics, nonlinear acoustics and noise control. He has published over 40 peer-reviewed scientific manuscripts, including articles published in Physical Review Letters and Physical Review X. His work has been featured by the Wall street journal, scientific American, Daily Mail, etc.