Researchers have fabricated a novel device that could dramatically boost the conversion of heat into electricity: a thin silicon membrane covered with nanopillars—standing columns of material no more than a few millionths of a meter in length. The technology could help recoup some of the heat energy that is wasted in the U.S. at a rate of about 100 billion dollars each year. Once the fabrication method is perfected, the silicon sheets could be wrapped around steam or exhaust pipes to convert heat emissions into electricity that could power nearby devices or be delivered to a power grid.