Nonlocal Mechanical Metamaterials Enabling Soliton Mode Conversion

Solitons are highly localized nonlinear wave excitations, and their propagation can display surprising complexity when nonlocal coupling is introduced. Herein, a mechanical metamaterial (MM) system with nonlocal interactions that exhibits a novel soliton behavior: upon encountering a boundary defect, elastic (nontopological) solitons undergo a mode conversion and form backward‐propagating topological solitons. This behavior contrasts sharply with that in local systems, where reflected solitons preserve their original form. The mode conversion is driven by a reshaped potential energy landscape and modified energy transfer pathways induced by nonlocality. Numerical simulations and theoretical analysis jointly confirm the consistency and repeatability of this phenomenon. These findings deepen the understanding of soliton transport and highlight the fundamental role of nonlocality in nonlinear dynamics, offering new pathways for tunable energy transport and wave‐based functionality in MMs.