Associate Professor of Practice, Lawrence Technological University, Michigan, USA

Abstract

Thermal transport in nanoscale materials constitutes a cornerstone of modern nanotechnology, enabling critical advances in thermoelectric energy conversion, nanoelectronics heat management, and phononic devices. The dominant heat carriers—phonons—exhibit markedly different transport behavior at the nanoscale due to boundary scattering, coherent effects, and modified phonon dispersion. Phonon engineering, the selective tailoring of phonon transport pathways via nanostructuring, interfaces, and defects, has been shown to significantly influence thermal conductivity in a wide array of materials. This research article provides a comprehensive review and original insights into phonon transport mechanisms, engineering strategies, and theoretical approaches underpinning thermal transport in nanoscale systems. We examine state-of-the-art methodologies, derive numerical models for ballistic vs. hydrodynamic phonon transport, and assess the implications for emerging technologies such as phononic crystals and 2D materials. Limitations and future research directions addressing multiscale modeling and experimental characterization are also presented.