This book unveils the physical principles of energy-harvesting transducers and explains the necessary physics and electronics background leading to the design of energy-harvesting power supplies. It explains in detail the available energy harvesting technologies, namely piezoelectric transducers, electrodynamic microgenerators, thermoelectric generators, solar cells, and radio and microwave frequency antennas. The subject coverage ranges from the physics of materials to the electronic engineering at the circuit level while explaining the fundamental relations of power transfer and management required in harvesting energy systems. Due to the intermittency of several sources of ambient energy (light, thermal, mechanic, electromagnetic radiation), the book also includes storage elements. Therefore, it explains and compares storage devices like solidstate thin-film lithium batteries, supercapacitors, and reversible fuel cells so the reader can select the most appropriate for a given application. On the electronics side, the book provides a detailed study about dc–dc switching regulators, including two fundamental subjects: matching loads and performance efficiency considerations. This last subject, hard to find even in power electronics books, is of paramount importance in the energy-harvesting context. The book ends by presenting application fields for energy-harvesting power supplies and examples of self-powered electronic system blocks for an energy-harvesting power supply and the design tradeoffs. This material illustrates the previous subjects while giving quantitative assumptions on environmental energy. The textbook includes prefaces, a table of contents, and an index.