Bogdan I. Popa's Research Group
Bogdan I. Popa
Associate Professor, Mechanical Engineering
2350 Hayward St
Ann Arbor, MI 48109-2125
Office: 3680 G.G. Brown
My broad research interest is on controlling the propagation of mechanical and electromagnetic waves with smart complex structures to influence physical processes in prescribed ways, to image and gain new knowledge on the surrounding environment, and/or to manipulate the perception of remote events. This is a dynamic, interdisciplinary area at the intersection between mechatronics, computer science, wave physics, and engineering with applications in air- and underwater acoustic imaging and sensing, biomedical engineering, telecommunications. I am currently pursuing several directions of research, which are summarized below.
Keywords: metamaterials, acoustics, electromagnetics, wave-matter interactions, inverse problems, imaging, artificial perception, machine learning
Metamaterials - materials with carefully controlled microstructure - enable the manipulation of physical waves in new and unconventional ways. We embed active elements (analog and digital electronic circuits, microcontrollers, etc.) in the metamaterial fabric to obtain new generation of programmable, smart materials with functionalities and physical properties going beyond traditional media. These active media find impactful applications in many areas including sensing, imaging, communications, and healthcare. Representative Papers: Popa et al, Nature Communications, 2018; Kovacevich and Popa, Applied Physics Letters, 2022
Complex Media Dynamics
Complex media such as biological tissue have complicated anisotropic physical properties (e.g. stiffness tensor, Willis coupling tensors) that depend on direction and are important to measure. For example, they may inform on the tissue health. We probe complex media with mechanical waves and process the scattered fields to learn the media dynamics using an array of methods including physics-based machine learning algorithms. This research has applications in the non-destructive evaluation of media, the design and characterization of metamaterials, and healthcare. Representative Papers: Zhai et al, Communications Materials, 2022; Cheong et al, Frontiers in Physics, 2022
Bioinspired Acoustic Imaging
Marine mammals such as dolphins are excellent at using ultrasound to discover and navigate their underwater environment. Their biosonar is significantly more advanced than any human-made sonar. We look at dolphins for inspiration to understand how to efficiently use ultrasound to map the environment and classify the objects within. We use this knowledge to create new sensing solutions for autonomous vehicles and acoustic imaging devices such as sonar and medical ultrasound scanners.
National Science Foundation
Office of Naval Research
Ground Vehicle Research Center (US Army) through the Automotive Research Center