%0 Journal Article
%T Thermal Transport across Solid Interfaces with Nanoscale Imperfections: Effects of Roughness, Disorder, Dislocations, and Bonding on Thermal Boundary Conductance
%A Patrick E. Hopkins
%J ISRN Mechanical Engineering
%D 2013
%R 10.1155/2013/682586
%X The efficiency in modern technologies and green energy solutions has boiled down to a thermal engineering problem on the nanoscale. Due to the magnitudes of the thermal mean free paths approaching or overpassing typical length scales in nanomaterials (i.e., materials with length scales less than one micrometer), the thermal transport across interfaces can dictate the overall thermal resistance in nanosystems. However, the fundamental mechanisms driving these electron and phonon interactions at nanoscale interfaces are difficult to predict and control since the thermal boundary conductance across interfaces is intimately related to the characteristics of the interface (structure, bonding, geometry, etc.) in addition to the fundamental atomistic properties of the materials comprising the interface itself. In this paper, I review the recent experimental progress in understanding the interplay between interfacial properties on the atomic scale and thermal transport across solid interfaces. I focus this discussion specifically on the role of interfacial nanoscale ¡°imperfections,¡± such as surface roughness, compositional disorder, atomic dislocations, or interfacial bonding. Each type of interfacial imperfection leads to different scattering mechanisms that can be used to control the thermal boundary conductance. This offers a unique avenue for controlling scattering and thermal transport in nanotechnology. 1. Introduction As the world¡¯s population and power demands increase, our technological solutions continue to rely on power-hungry applications. The shear population increase in the world along with skyrocketing electricity, power, and transportation needs in emerging markets has led to necessary minimum levels of energy for sustainable growth and livelihood of human kind. The trends in energy use are marked by our society¡¯s continued advancement of technology, communication, transportation, and quality of life. For example, in 2010, the United States used an estimated 28.7 trillion kW-h of energy [1]. These massive energy demands both in the USA and abroad are a necessary requirement for continued capabilities and qualities of life that have been made possible with the advancement of technologies. For example, increased computing needs (internet, cloud computing, and wireless communications), although more energy efficient in the recent past, have led to an increase in data center energy usage by roughly a factor of six over the past decade [2]; although technologies have become more energy efficient, due to the shear increase in the numbers of users and
%U http://www.hindawi.com/journals/isrn.mechanical.engineering/2013/682586/