Interaction of acoustic and electromagnetic waves for thermoacoustic imaging and vibration sensing

Abstract

Acoustic wave and electromagnetic wave can interact and lead to rich physical phenomenon to be used for applications such as medical diagnosis, non-destructive material characterization, and remote sensing. In this talk, I will present our research studies on two ways acoustic and electromagnetic waves interact with each other: (1) When pulsed microwave is absorbed by tissue, thermoacoustic waves are generated through thermal expansion. We explored the sensing and processing of thermoacoustic waves generated by a pulsed microwave ablation antenna as a potential way for monitoring the ablation process in real time. (2) Electromagnetic waves such as Wi-Fi signals and light can be modulated by acoustic/mechanical vibrations in the environment. We developed non-contact vibration sensing systems based on such modulations, and also developed a metamaterial-based vibration amplification device that can enhance the vibration magnitude sensitivity over a broad range of vibration frequencies.