A shirt can generate electricity to run small electronic devices say, for soldiers in the field, hikers and others whose physical motion could be harnessed and converted to electrical energy. Here the dress contains fibers covered with zinc oxide nanowires to generate electrical current due to piezoelectric effect. Collecting current flow from many fiber pairs woven into the dress due to the body movement can run a range of portable electronic devices. The same principle can be adopted to produce current by having fibers woven into curtains, tents or other structures to capture energy from wind motion, sound vibration or other mechanical energy.
Principle
The microfiber-nanowire hybrid system is built on the nanowire nanogenerator. This system generates current from arrays of vertically-aligned zinc oxide (ZnO) nanowires that flex beneath an electrode containing conductive platinum tips. Uniquely coupled piezoelectric and semiconducting zinc oxide nanostructures produce small electrical charges when they are flexed. The microfiber generators rely on the same principles, but are made from soft materials and designed to capture energy from low-frequency mechanical energy. They consist of DuPont Kevlar fibers on which zinc oxide nanowires have been grown radially and embedded in a polymer at their roots, creating what appear to be microscopic brushes with billions of bristles. One of the fibers in each pair is also coated with gold to serve as the electrode and to deflect the nanowire tips. The two fibers scrub together just like two brushes with their bristles touching, and the piezoelectric-semiconductor process converts the mechanical motion into electrical energy. Many such devices can be hooked together to produce higher power output.
Output
The nanogenerators of two by three millimeters square size can produce up to 800 nanoamperes and 20 millivolts. A square meter of fabric made from the special fibers could theoretically generate as much as 80 milliwatts of power.