Researchers at the Massachusetts Institute of Technology (MIT) unveiled a new material that generates steam by soaking up sunlight. The sponge can be made from relatively inexpensive materials, and could find applications in small, steam-powered devices that are not effectively operated by solar-powered steam generators.
The sponge-like material, developed by MIT mechanical engineer Hadi Ghasemi, consists of a layer of graphite flakes on top of carbon foam that float on a layer of liquid, including water. When sunlight hits the structure’s surface, it creates a hot spot in the graphite, drawing water up through the porous material, where it evaporates as steam.
Thus far, the material has been able to convert 85% of sunlight into steam—far more efficient than existing methods. Furthermore, the setup loses very little heat in the process, and can produce steam at relatively low solar intensity. The advance could be used not only as a cost-effective and emission-free source of steam energy, but also for desalination and sterilization.