A vision to supply microelectronic devices without batteries making them perpetual or extending time of service in battery-oriented mobile supply schemes is the driving force of the research related to ambient energy harvesting. Energy harnessing aims thus at extracting energy from various ambient energy “pools”, which generally are cost- or powerineffective to be scaled up for full-size, power-plant energy generation schemes supplying energy in electric form. These include – but are not limited to - waste heat, electromagnetic hum, vibrations, or human-generated power in addition to traditional renewable energy resources like water flow, tidal and wind energy or sun radiation which can also be exploited at the miniature scale by energy scavengers. However, in case of taking advantage of energy harvesting strategies to power up sensors monitoring environment inside buildings adaptable energy sources are restrained to only some which additionally are limited in spatial and temporal accessibility as well as available power. The paper explores experimentally an energy harvesting scheme exploiting human kinesis applicable in indoor environment for supplying a wireless indoor micro-system, monitoring ambient air properties (pressure, humidity and temperature).
Almost all environments are now being extensively populated by miniaturized, nano-powered electronic sensor devices communicated together through wireless sensor networks building Internet of Things (IoT). Various energy harvesting techniques are being more and more frequently proposed for battery-less powering of such remote, unattended, implantable or wearable sensors or other low-power electronic gadgets. Energy harvesting relays on extracting energy from the ambient sources readily accessible at the sensor location and converting it into electrical power. The paper exploits possibility of generating electric energy safely accessible for nano-power electronics using tribo-electric and electrostatic induction phenomena displayed at super-hydrophobic surfaces impinged by water droplets. Mechanism of such interaction is discussed and illustrated by experimental results.