Manipulation of radiative and conductive heat transfer through nanostructures

<p dir="ltr">Heat transfer, an old and fundamental field with roots tracing back to Fourier’s heat conduction theory in 1822, is experiencing revolutionary transformation under the scope of nanotechnology. Traditional understanding of thermal processes is being dramatically reimagined since materials and structures could be manipulated at the nanoscale, enabling unprecedented control on heat exchange and dissipation. In this dissertation, the unique physical properties of nanostructures are leveraged to provide unprecedented control over both radiative and conductive heat transfer processes that cannot be obtained in the macroscopic world. We start with the investigation of near-field radiative heat transfer (NFRHT) between SiN phonon-polaritionic structures combined with plasmonic nano-resonators such as split ring resonators (SRRs). With custom-built nanodevices and well-designed simula?tions, colossal enhancement is confirmed on NFRHT between SiN-SRR composite structures, with the physical origin attributed to strong coupling between two polaritonic modes. Then, we switch gear to dynamic control over far-field thermal radiation processes, where VO2 and GeTe phase change materials are integrated with mid-infrared metasurface emitters to achieve tunable narrow-band emission. Furthermore, regarding the unprecedented heat dissipation problem in nanoelectronics and semiconductor industries, a high-performance thermal interface material based on electroplated copper nanowire array is proposed, fabricated, and tested, which shows superior thermal performance compared with state-of-the-art products on the market.</p>