Meta-Surface Design Optimization for Controlling the Surface Waves Propagation

This project will promote the progress of science and advance the national security and welfare, by generating new fundamental knowledge on the control of surface wave motion. Surface waves (e.g., vibration) are generated by natural and human-made sources, such as earthquakes, explosions, traffic and construction operations. Many electronics also use the principles of surface wave propagation inside the devices. The ability to control surface wave motion has broad implications across length scales: from design of miniature electronic devices to earthquake or vibration isolation of critical structures. This award supports fundamental research needed to purposefully control the propagation of surface waves by modifying the surface conditions to reflect or divert wave energy. This project will provide multi-disciplinary training and career preparation for participating graduate students. The research team will incorporate the methods and findings of the research into graduate and undergraduate courses, as well as secondary level teaching at K-12 schools in Pennsylvania and across the country through a collaboration with the Center for Science and the Schools (CSATS).

The project presents a novel approach for controlling surface wave motion based on a fundamental study of the boundary conditions' influence on the surface wave propagation. This enables implementation of a rational design philosophy for meta-surfaces to control Rayleigh surface waves. The boundary-condition (BC) based strategy will be implemented in order to create a resonant meta-surface to minimize the transmitted energy in a prescribed frequency bandwidth to a particular location. An optimization procedure will be developed to find the optimal resonator topology such that the desired BCs are satisfied and to determine the resonator spacing. A method to broaden the frequency stopband will be tested. This approach is fundamentally different from the commonly used frequency tuning and parametric design process. Since the BCs are frequency-independent, the new approach is transportable across length scales.

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.