Researchers at MIT’s Department of Mechanical Engineering have developed a simple, graphite and carbon-based sponge that soaks up water and heats it using the sun’s rays. The sponge converts the water into steam that can then be used for water purification or as a power source. With low-cost materials and an 85 percent efficiency rate, the invention has the potential to become an extremely cost-effective source of solar-derived clean water and steam power for remote or developing areas.