Introduction

Micromachines are very small material structures, simple mechanisms, and complex integrated systems that perform mechanical work in response to an external stimulus. Micro-cantilever beams are commonly found in miniature light-driven machines and integrated systems. The relationship between light and electromagnetism was first established in 1845 when Michael Faraday discovered that for a transparent dielectric material, the plane of polarization of a linearly polarized light is rotated when the light rays travel along the direction of the magnetic field. Although the force of light would have little impact on practical engineering applications, the possibility of trapping and manipulating objects in a light beam inspired the imagination of numerous science fiction writers for more than a century. By 1873 James Maxwell had explained the behavior of electric and magnetic fields associated with light waves and proposed that these self-propagating electromagnetic waves travel at a constant speed. The chapter also presents an overview of the key concepts discussed in this book.