Prof. Popa’s 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. Prof. Popa is currently pursuing several directions of research, which are summarized below.
Smart metamaterials: Materials with carefully controlled microstructure (metamaterials) enable the manipulation of physical waves in new and unconventional ways. The Popa group uses machine learning algorithms to design these structures and 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.
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. The Popa group probes complex media with mechanical waves and processes the scattered fields to learn the media dynamics using an array of methods including physics-based machine learning algorithms.
Bioinspired robotic perception: 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. The Popa group uses neural networks to model the perception of echolocating dolphins with the goal of replicating these animals’ outstanding ability to use ultrasound to map the environment and classify the objects within.
