Strain-Engineered Anisotropic Thermal Transport in Layered MoS₂ Structures

Strain engineering offers a precise and reversible approach to modulating thermal transport in layered materials, which is critical for next-generation electronics and energy systems. In this work, we unveil how homogeneous and heterogeneous strains modulate the anisotropic thermal conductivity of layered molybdenum disulfide using molecular dynamics simulations with registry-dependent interlayer force fields. A homogeneous compressive cross-plane strain of 10% induces a nearly 5-fold enhancement in cross-plane thermal conductivity, while a tensile strain of 5% suppresses it by over 68%. Heterogeneous strain further enables fine control of cross-plane thermal conductivity through strain-gradient-dependent moiré superlattice formation, which disrupts interlayer phonon coupling. In contrast, the in-plane thermal conductivity remains robust under heterogeneous strain, decreasing by approximately 12% under a tensile strain of 3.1%. We attribute this asymmetric thermal response under heterogeneous strain to distinct mechanisms: cross-plane thermal conductivity is governed by a strain-sensitive interlayer registry, while in-plane thermal conductivity relies on in-plane bonding rigidity. Our study demonstrates that homogeneous and heterogeneous strains can serve as effective and universal methods for modulating the in-plane and cross-plane thermal conductivity of various layered materials. These insights advance the design of strain-engineered thermal management systems.