- Letter
Programmable topological and hybrid interface modes in a resonant piezoelectric metamaterial
Phys. Rev. Applied 25, L051005 – Published 20 May, 2026
DOI: https://doi.org/10.1103/c6y7-3tbn
Abstract
We experimentally demonstrate topological and hybrid interface modes in a locally resonant piezoelectric metamaterial beam for flexural waves, supported by high-fidelity finite-element simulations. By employing digitally controlled synthetic impedance shunt circuits, the translational symmetry of a periodic piezoelectric beam is broken, inducing energy localization consistent with a Su-Schrieffer-Heeger-like model. Band folding via resonant shunts introduces sub-Bragg Dirac degeneracies, which are subsequently opened by alternating the inductance values of shunt circuits connected to piezoelectric elements. We experimentally validate the energy localization within the subwavelength bandgaps, as well as programmable spatial control of the localization by reconfiguring the shunt inductances of the piezoelectric unit cells. Additionally, varying the local circuit resonances enables frequency-wise tunability of the topological and hybrid interface modes. The versatility of programmable interface modes enables performance enhancement across diverse applications, including acoustic communication, targeted energy transfer, and energy harvesting. This capability is further demonstrated through a brief case study on energy harvesting by placing a resistive electrical load near the interface.
