Transistors play a central role in many electronic circuits, where they usually function as either a switch or an amplifier. This book reviews research in the field of transistors including a new class of transistors whose channels are made from semiconducting carbon nanomaterials, the evolution of these designs and the highlights of the work that has driven their development. Also discussed, herein, are the electronic properties and self-consistent simulations of carbon nanotubes in transistor technology, the future developments in the nanowire field-effect transistor research area, the implementation of chaotic oscillators by using transistors designed with CMOS integrated circuit technology and others.