Point-to-point elastic-wave energy concentration in thin plates via a pair of coupled meta-atoms

Manipulating the spatial concentration of elastic-wave energy in thin plates is a fundamental challenge within applications ranging from energy harvesting to structural health monitoring. Existing approaches typically rely on active transducer arrays or large-scale elastic metamaterials, limiting their implementation in compact passive systems. Here, we propose a minimal, array-free strategy for point-to-point elastic-wave energy concentration using only a pair of passive meta-atoms. An analytical scattering model is developed under Kirchhoff plate theory, and a closed-form enhancement factor is derived to quantify the localized displacement amplification at a prescribed target location. The analysis shows that energy concentration is governed by coupled monopole resonances and exhibits a distinct distance-dependent behavior: the enhancement first oscillates with increasing separation and then transitions into a far-field stabilized regime. Owing to the coexistence of propagating and evanescent scattering channels in elastic waves, the proposed mechanism yields substantially stronger enhancement than its acoustic analogue. The theoretical predictions are validated by finite element methods (FEM) and experiments, and the potential implication of the coupled-resonance mechanism is further demonstrated through weak signal recovery under broadband noise. These findings provide a quantitatively validated scattering-theory description of point-to-point elastic-wave energy concentration and offer physical insight into compact passive wave manipulation in elastic continua.