Introduction

Abstract

Abstract The major sources of inspiration for this book are the recent rapid advancements in microtechnology and nanotechnology. Microtechnology deals with devices and materials with characteristic lengths in the range of submicron to micron scales (0.1-100 µm), while nanotechnology generally covers the length scale from 1 to 100 nm. For example, integrated circuits are now built on transistors with characteristic device length scales around 100 nm. The semiconductor industry roadmap predicts that, in 2010, the characteristic length in integrated circuits will further shrink to 25 nm (SEMATECH, 2002). In the late 1980s, microelectronics fabrication technology began to impact mechanical engineering, and the field of microelectromechanical systems, or MEMS, blossomed (Trimmer, 1997). Meanwhile, nanoscience and nanotechnology, explored by a few pioneers (Feynman, 1959, 1983), are currently generating much excitement across all disciplines of science and engineering. The fields of micro- and nanotechnologies are enormous in breadth and cannot be covered completely in any single book. In this book, we focus on microscopic mechanisms behind energy transport, particularly thermal energy transport. As the device or structure characteristic length scales (such as the gate length in field-effect transistors, used to build computers, and the film thickness in coatings) become comparable to the mean free path and the wavelength of energy and information carriers (mainly electrons, photons, phonons, and molecules), some of the classical laws are no longer applicable. By examining the microscopic pictures underlying transport processes, we will develop a consistent framework for treating thermal energy transport phenomena from the nanoscale to the macroscale.