Energy harvesting (EH) – also known as power harvesting, energy scavenging, or ambient power – is the process by which energy is derived from external sources, then stored for use by small, wireless autonomous devices, like those used in wearable electronics, condition monitoring, and wireless sensor networks.

MEMS is the technology of microscopic devices incorporating both electronic and moving parts. MEMS are made up of components between 1 and 100 micrometres in size, and MEMS devices generally range in size from 20 micrometres to a millimetre, although components arranged in arrays can be more than 1000 mm2. They usually consist of a central unit that processes data and several components that interact with the surroundings.