U.S. researchers say they've produced a new class of solar cells that can repair themselves much like plants do through photosynthesis. By using carbon nanotubes and DNA, scientists at Purdue University have developed solar technology aimed at increasing service life and reducing cost, a university release said Tuesday. "We've created artificial photosystems using optical nanomaterials to harvest solar energy that is converted to electrical power," Jong Hyun Choi, a Purdue professor of mechanical engineering, said. Photoelectrochemical cells that convert sunlight into electricity contain light-absorbing dyes called chromophores, similar to chlorophyll molecules in plants, that degrade due to exposure to sunlight. "The critical disadvantage of conventional photoelectrochemical cells is this degradation," Choi said. The new technology gets around this problem in the same way nature does, by continuously replacing the photo-damaged dyes with new ones. "This sort of self-regeneration is done in plants every hour," Choi said.