This topic addresses control of acoustic and elastic wave propagation using both active and passive phononic crystals (PnC) and resonant metamaterials (RMM), which are typically architected materials composed of periodic unit cells. The performance of these materials depends not only on the constitutive materials used for their composition but also the structural configuration of their unit cell, requiring competency in both material science and structural dynamics. One goal of this research is the development of material systems (e.g. electromechanical, magnetorheological, thermoelastic, etc.) that can be processed via additive manufacturing to create tunable PnC/RMM capable of changing their dynamic behavior in response to external stimuli. Another goal is the development of techniques to aid in the design of the unit cell architecture to enable novel effects (e.g. optimization, numerical modeling, analytical relationships, etc.). The overarching objective of this research area is to solve practical Air Force problems using PnC/RMM phenomena like negative effective properties, non-reciprocity, non-linearity and interface effects (e.g. boundary conditions, lattice defects, topological edge modes). Common Air Force applications include aeroacoustics, vibration reduction, noise reduction, and impact resistance. 

1. Electrically tunable auxetic behavior of shunted piezoelectric elements. Carson L, Willey, Phillip R. Buskohl, Abigail T. Juhl. Journal of the Mechanics and Physics of Solids, Vol 137, 103873. 2020.

2. A reconfigurable magnetorheological elastomer acoustic metamaterial. CL Willey, VW Chen, KJ Scalzi, PR Buskohl, AT Juhl. Applied Physics Letters, 117 (10), 104102. 2020.

3. Adaptive elastic metastructures from magneto-active elastomers. Connor D Pierce, Carson L Willey, Vincent W Chen, James O Hardin, J Daniel Berrigan, Abigail T Juhl, Kathryn H Matlack. Smart Materials and Structures 29 (6), 065004. 2020.

key words

Elastic metamaterials; Acoustic metamaterials; Periodic structures; Responsive Materials; Phononic Crystals; Wave propagation

Citizenship:  Open to U.S. citizens

Level:  Open to Postdoctoral and Senior applicants