Abstract

Advances in micro-electronics and miniaturized mechanical systems are\nredefining the scope and extent of the energy constraints found in battery-operated wireless\nsensor networks (WSNs). Ambient energy harvesting may prolong the systems’ lifetime, or\npossibly enable perpetual operation. Also wireless energy transfer allows systems to\ndecouple the energy sources from the sensing locations, enabling deployments previously\nunfeasible.The discussion is instrumental to providing a foundation for selecting the most\nappropriate energy harvesting or wireless transfer technology. [3].