Engineers at the University of Viskonsis-Madison developed a technology that allows to extract energy from man foot movement. Scientists plan to create a portable device that extracts energy from a renewable source, and having enough power to charge mobile devices. Their invention is based on the effect of electro-wetting on dielectric (Electro-wetting on dielectric - EWOD).
Engineers created a device made from a drop of particular compounds of mercury, placed between two conductive plates coated with an insulating layer of thallium oxide. Power of such devices is very low, but with an area of 40 square centimeters it can make up to 10 watts of power. Scientists plan to test their invention, placing the battery in shoes of similar design.