Piezoelectricity is the electrical charge generated when specific materials such as crystals, certain ceramics, and some types of biological material undergo mechanical stress. It is yet another promising tool in the effort to find new, clean non-fossil fuel energy substitutes. With new developments in advanced engineered materials and in nanotechnology, devices can be made that take advantage of that ability to convert motion or stress to electrical energywhether from movement, friction, changes in pressure, or other types of mechanical stress. This book provides an overview of the methods and applications of harvesting energy using piezoelectric materials. It presents harvesting methodologies to evaluate the potential e?ectiveness of di?erent techniques. Piezoelectric energy harvesters have many applications including sensor nodes, wireless communication, micro electromechanical systems, hand-held devices and mobile devices. The book even presents new developments in harvesting electrical energy from raindrops!