Space-time wave localization in electromechanical metamaterial beams with programmable defects

A relevant feature for various applications of phononic crystals and metamaterials is the wave localization and guiding using defects introduced into a periodic array. In this context, we present a flexible localization of elastic waves in piezoelectric metamaterial beams with space- time-modulated defects. The vibration energy, originally confined in a point defect, is gradually manipulated in space and time as the inductances of the shunt circuits of subsequent unit cells are properly controlled, perfectly inducing energy localization at the final defect position. This wave localization by programmable defects is also applied to a two-dimensional triangular lattice composed by piezoelectric metamaterial beams, which illustrates the potential and versatility of the proposed strategy in more complex systems. The space-time modulation of point defects presented in this work opens new possibilities for programmable wave localization, and hence, manipulation of vibration energy or information using smart metamaterials, with applications that may involve guiding, sensing, monitoring and energy harvesting.

Automated summary

This paper presents a method for flexible localization of elastic waves in piezoelectric metamaterial beams by controlling the inductance of shunt circuits to gradually manipulate vibration energy in space and time, resulting in energy localization at the defect position. The programmable wave localization through defects demonstrates the potential and versatility in complex systems.