Abstract
Harvesting energy from the environment is a desirable and increasingly important capability in several emerging applications of smart sensing systems. Due to the low-power characteristics of many smart-sensor systems, their energy harvesting systems (EHS) can achieve high efficiency by emphasizing low overhead in maximum power point tracking (MPPT) and the use of super capacitors as a promising type of energy storage elements (ESE). Considerations in designing efficient charging circuitry for super capacitors include leakage, residual energy, topology, energy density, and charge redistribution. This chapter first reviews ambient energy sources and their energy transducers for harvesting, followed by descriptions harvesters with low-overhead efficient charging circuitry and super capacitor-based storage. © Springer International Publishing Switzerland 2015.