Use Your Shirt to Charge Your iPod?
iPod or cell phone running low on juice? What if you could plug it into your shirt to recharge the batteries! According to a report on Reuters, scientists at the Georgia Institute of Technology have developed a technology to allow a microfiber fabric to generate electricity. Enough to power a cell phone or MP3 player in fact. The act of walking or standing in a breeze would be enough to generate 80mW per square meter. Obviously, those of you with, um, larger builds will get more use out of this than the rest of us.
Calling it a "nano-based microgenerator" the shirt makes good use of zinc oxide nanowires, which ave semiconductive properties. These wires are 1000 times smaller than the width of a human hair and are embedded within the microfiber fabric in a sort of paired brush configuration, with the ends facing out from center. Since one fiber in each pair is coated with gold, it works as an electrode. The motion takes the mechanical energy and creates electricity.
The technology is fascinating, and the scientists actually found a way to cause the wires to "grow" onto the polymer-coated fibers. The process can be done with any conductive fiber. Additional steps provide protection and the gold coating which enables the electrode performance.
At this point the invention is being demonstrated as principle and no manufacturing techniques have been designed or realized. The mechanics are there, however they did find that zinc oxide degrades when wet (oops, can't wash this shirt!) With this in mind there are several hurdles before we can recharge small portable devices through mechanical-electrical conversion.