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.