Thermal transport at a solid-nanofluid interface: from increase of thermal resistance towards a shift of rapid boiling.

We use molecular dynamics simulations to investigate interfacial thermal transport between an ethanol suspension containing gold atomic clusters and a gold surface, using both realistic and simplified molecular models of nanoparticles. The interfacial thermal conductance was determined via a thermal relaxation method for a variety of nanoparticle-nanoparticle and nanoparticle-surface interaction strengths. The Kapitza resistance is found to increase due to the presence of nanoparticles in the vicinity of the solid-liquid interface.

Solid-Liquid Interface Thermal Resistance Affects the Evaporation Rate of Droplets from a Surface: A Study of Perfluorohexane on Chromium Using Molecular Dynamics and Continuum Theory.

We study the role of solid-liquid interface thermal resistance (Kapitza resistance) on the evaporation rate of droplets on a heated surface by using a multiscale combination of molecular dynamics (MD) simulations and analytical continuum theory. We parametrize the nonbonded interaction potential between perfluorohexane (CF) and a face-centered-cubic solid surface to reproduce the experimental wetting behavior of CF on black chromium through the solid-liquid work of adhesion (quantity directly related to the wetting angle). The thermal conductances between CF and (100) and (111) solid substrates are evaluated by a nonequilibrium molecular dynamics approach for a liquid pressure lower than 2 MPa.

Thermal Transport at Solid-Liquid Interfaces: High Pressure Facilitates Heat Flow through Nonlocal Liquid Structuring.

The integration of three-dimensional microelectronics is hampered by overheating issues inherent to state-of-the-art integrated circuits. Fundamental understanding of heat transfer across soft-solid interfaces is important for developing efficient heat dissipation capabilities. At the microscopic scale, the formation of a dense liquid layer at the solid-liquid interface decreases the interfacial heat resistance.

Blocking Phonon Transport by Structural Resonances in Alloy-Based Nanophononic Metamaterials Leads to Ultralow Thermal Conductivity.

Understanding the design rules to obtain materials that enable a tight control of phonon transport over a broad range of frequencies would aid major developments in thermoelectric energy harvesting, heat management in microelectronics, and information and communication technology. Using atomistic simulations we show that the metamaterials approach relying on localized resonances is very promising to engineer heat transport at the nanoscale. Combining designed resonant structures to alloying can lead to extremely low thermal conductivity in silicon nanowires.

Functionalization mediates heat transport in graphene nanoflakes.

The high thermal conductivity of graphene and few-layer graphene undergoes severe degradations through contact with the substrate. Here we show experimentally that the thermal management of a micro heater is substantially improved by introducing alternative heat-escaping channels into a graphene-based film bonded to functionalized graphene oxide through amino-silane molecules. Using a resistance temperature probe for in situ monitoring we demonstrate that the hotspot temperature was lowered by ∼28 °C for a chip operating at 1,300 W cm(-2).

Ultracompact interference phonon nanocapacitor for storage and lasing of coherent terahertz lattice waves.

We introduce a novel ultracompact nanocapacitor of coherent phonons formed by high-finesse interference mirrors based on atomic-scale semiconductor metamaterials. Our molecular dynamics simulations show that the nanocapacitor stores coherent monochromatic terahertz lattice waves, which can be used for phonon lasing-the emission of coherent phonons. Either one- or two-color phonon emission can be realized depending on the geometry of the nanodevice.

Diamond-Structured Photonic Crystals with Graded Air Spheres Radii.

A diamond-structured photonic crystal (PC) with graded air spheres radii was fabricated successfully by stereolithography (SL) and gel-casting process. The graded radii in photonic crystal were formed by uniting different radii in photonic crystals with a uniform radius together along the Г‑Х direction. The stop band was observed between 26.