http://www.newsweek.com/electricity-generated-air-water-molecules-nanopores-1802786

Researchers at the University of Massachusetts Amherst have found a way to generate electricity by harvesting moisture in the air.

According to a paper published in the journal Advanced Materials, electricity can be harvested from air using a device made of nearly any material, merely requiring the material to be dotted with nanopores less than 100 nanometers (nm)—0.000004 inches—in diameter.