By turning powders into fibers using carbon nanotube webs, researchers at the University of Texas have managed to make yarn that can clean itself and work as a battery. It also happens to be a superconductor, but most importantly, it's machine-washable.
You may not think about it, but a lot of the cool technologies that we depend on every day rely on powders to work. Lithium ion batteries, for example, use a fine powder with a huge surface area as an electrode to store energy. This is great, except powders are messy, and you can't really use them in non-rigid applications.
One way to get around this problem is to use nanotubes, those magical carbon structures that are capable of just about anything. As it turns out, you can stretch bunches of nanotubes into a web of sorts, and if you spray that web with powder and then twist it up, you get a piece of nanotube string that's between 95% and 99% powder by weight. Since the powder is trapped in the twists of the web, you end up with a lightweight, cheap, durable and washable piece of yarn with all of the properties of the powder inside.
The upshot of this technique is that you can make yourself a piece of fabric that is, for all intents and purposes, one giant battery. You're not weaving batteries into the fabric, the battery is the fabric. Happily, the University of Texas is already working with carbon-nanotube textile maker Nanocomp to try and bring this stuff to the commercial market.