NSF Award
2219203
This project is study metamaterials to achieve desired behaviors and functions that would be hard, if not impossible, to find in naturally occurring materials. Metamaterials have broad applications in numerous industries and defense that can revolutionize use-cases such as noise mitigation, vibration isolation, energy harvesting, radar and sonar, and sensor development. A fundamental issue with metamaterials research is that the dynamic response of such systems near their boundaries is currently poorly understood, especially in contrast to their response in their interior. This deficiency has slowed the transition of the technology of metamaterials from research to industry. This award supports fundamental research to provide needed knowledge for the understanding of the boundary and interface issues in metamaterials research. It involves several disciplines including acoustic and elastic metamaterials, inverse design and optimization, and materials science. The multi-disciplinary approach will help positively impact engineering education of the future. The team will perform theoretical and computational analysis of transition layers and use inverse design principles to create devices that control propagation of mechanical waves. They will also conduct experiments to verify the models and test the performance of the devices created. <br/><br/>The broad technical goal of this grant is to provide a consistent method for the solution of dynamic boundary value problems on finite domains of acoustic and elastic metamaterials. Current approaches either involve micromorphic theories (with a very high number of material parameters) or exact but nonlocal boundary conditions (formulated with Fredholm integral equations). The former is incompatible with much of the machinery of metamaterial device design (such as transformation methods) and the latter is complex enough to make its use at the moment nearly untenable. As a consequence, ideal metamaterial designs, when realized in practice, demonstrate significant and poorly understood performance degradations. Through this grant, the team seeks to solve this issue by 1) utilizing and focusing on local metamaterials and 2) coupling them with transition layers. It is hypothesized that these two ideas will make it tractable to solve a wide range of boundary value problems involving arbitrary finite samples, thus overcoming a critical obstacle in the field. The technological promise of mechanical metamaterials is hinged upon accurate modeling of scattering off such designs, which is significantly affected by the handling of interfaces. This grant seeks to overcome this major obstacle towards robust designs of micro-structured media.<br/><br/>This project is jointly funded by Mechanics of Materials & Structures (MOMS) Program and Dynamics, Control and Systems Diagnostics (DCSD) Program.<br/><br/>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.
