The Center for Nanotechnology and Molecular Materials at Wake Forest University has developed a new material they call Power Felt. The fabric can convert body heat into an electrical current. It’s made of carbon nanotubes held within plastic fibers and the material has the same look and feel of felt, a material well known for keeping in the heat.
When held close to a warm body or other heat source the Power Felt take advantage of temperature differences and create a charge. That means power can be generated just by insulating something. It can be used to charge a mp3 player or a smartphone, but also for something far more interesting. If used to insulate pipes or buildings you could theoretically generate a charge while you turn on your taps, or just being at home.