A team of scientists at the Berkeley Sensor and Actuator Center at UC Berkeley have created nanofibers that can generate up to 30 millivolts of electricity, but are only a hundredth as thin as a human hair. This breakthrough could lead to the creation of clothing with nanofibers woven into them, allowing people to charge their electronic devices from their clothes!
The fibers also displayed piezoelectric properties, which means if they are mechanically stretched or twisted, the built-up mechanical energy can be converted to electric energy. This means that the fibers themselves could be powered up with normal body movements.
Source: UC Berkeley.