Capillary driven electrokinetic generator for environmental energy harvesting

Abstract We propose a novel electrokinetic generator driven by the capillary force. By coupling the capillary with water evaporation, the generator can output power as long as water evaporation exists, thus it can harvest environment energies from waste heat, wind power to solar energy. Experimental results show that a capillary driven electrokinetic generator, with evaporation area of 4.9 cm2 and fluidic channel area of 2 mm2, can output maximum electrical voltage of ∼40 mV and current of 9.6 μA. The voltage and current can both be greatly enhanced by reducing the area of fluidic channel, approaching maximum power of 0.22 mW according to the theoretical calculations. In addition, a live-tree driven electrokinetic generator with an output electrical power of 2.7 μW is demonstrated. These results show that the capillary driven electrokinetic generator is of promising potential in self-powered systems.