Scientists at MIT have built nanotubes that act like tiny antennas, or funnels, that can concentrate sunlight on a solar cell. Regular solar cells capture only a relatively small portion of the light that hits them, mainly because the materials used to build the cells naturally absorb some wavelengths of light and reflect others. Carbon nanotubes specially designed to capture and funnel as much light as possible at all wavelengths could solve that problem. Nanotube antennas could result in solar cells that are much smaller but also more powerful than today’s commercial cells. At the moment, though, such cells are only a theoretical possibility. Researchers need to work out dozens of technical details before nanotube powered solar cells become a reality.