Designing small structures necessitates an understanding of various device behaviors. The way to gain that understanding is to build, analyze, and interpret the proper mathematical models. Through such models, this book illuminates microscale and nanoscale phenomena, and thereby facilitates the design and optimization of micro- and nanoscale devices. Each chapter focuses on a set of devices that share a common feature. The authors abstract that feature and present the mathematical tools needed to model it. This treatment not only provides the background and tools needed to design and optimize microdevices but also helps develop the intuitive understanding that can lead to developing new and better designs and devices.