Energy harvesting is the capture of external energy from various naturally occurring or prevalent sources. This harnessed energy is stored for or directly used in numerous applications, most particularly electronics and electrical systems. The scope, significance, and impact of energy harvesting research have generated a lot of interest within the scientific community and the general populace at large. A number of major advances in energy harvesting have relied on the identification and application of functionalities of existing materials or microsystems in innovative manners or with adapted designs.

This book aims to provide an overview of recent research advances utilizing functional materials and microsystems for energy harvesting. The emphasis of the coverage is on materials and devices, with resulting technologies capable of powering ultralow-power implantable sensors up to large-scale electrical grids. The book is presented as a collection of carefully selected contributions from international researchers from both academia and industry.

The nine contributed chapters cover four key themes, starting with design of microsystems, which enable and manage energy harvesting, before moving on to chapters dealing with functional materials that underpin major advances in energy harvesting technologies for thermal, solar, and mechanical energy.

Chapters 1 and 2 present approaches and circuit designs for energy harvesting, storage, and use. Chapter 3 reviews opportunities for the combination of thermoelectric materials and microsystems to contribute to energy harvesting, while Chapter 4 covers a breakthrough thermoelectric material technology utilizing thermopower waves as energy sources. Chapters 5 through 7 present a variety of solar cell configurations spanning polymer and monocrystalline silicon solar cells as energy sources for low-power electronics and with approaches for optimization of energy capture and conversion. Chapters 8 and 9 deal with harnessing mechanical energy from ambient sources using piezoelectric vibrational energy harvesters. Thin film materials for piezoelectric energy harvesting and a review of the designs and limitations of this approach are covered.

We hope this coverage of functional materials and microsystems for energy harvesting provides readers with an appreciation of the new and emerging research areas, as well as inspires further new ideas in a very significant research field.

Madha Bhaskaran and Sharath Sriram
RMIT University

Krzysztof Iniewski
CMCS Emerging Technologies Research, Inc.