Collaborative Research: Wave Engineering in 2D Using Hierarchical Nanostructured Dynamical Systems

This project studies the propagation of sound waves in a tailor-made two-dimensional medium. The medium is a periodic array of carefully designed nanoscale cavities with a single-atom-thick membrane stretched over them. When the membrane is vibrated, each cavity emits a high-frequency sound wave, much like a nanoscale drum. These waves can then be tuned, coupled to each other, propagated preferentially, or even completely canceled, thanks to the unique properties of the medium. As such, this study will advance our understanding of wave propagation in novel materials and develop the nanotechnology necessary for harnessing these waves. Among the numerous envisioned applications are electro-acoustic signal processing components intended for use in communications, national security, environmental monitoring, and biotechnology. The project also integrates research and education by fostering a research collaboration between a primarily undergraduate institution and a research-intensive university. The research, education, and mentoring opportunities will facilitate workforce development in an emerging area of technology. The overarching scientific goal of this project is to understand wave propagation in nanostructured dynamic systems with extreme linear dimensions. The studies will be carried out in a tailor-made dynamic system incorporating a single-atom-thick 2D material, such as graphene, into a periodic skeleton structure. This system will allow for coupling individual single-atom-thick acoustic resonators on a nanostructured compliant lattice, opening up new and exciting acoustic wave dynamics. Experimental access to these acoustic waves will be achieved by a variety of ultrasensitive optical and electrical transducers, and the waves will be characterized using amplitude and phase-sensitive techniques. Furthermore, the acoustic properties of this dynamic system can be tuned by applying external perturbations, which will allow for harnessing its unique attributes in possible radiofrequency device applications. This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.