A new material designed by MIT researchers can convert sunlight into steam with 85 percent efficiency. The material was created in part with a microwave and has the potential to make huge changes in sterilization, desalination and even solar thermal power.
Developed by MIT mechanical engineer Hadi Ghasemi, the material has a thin double-layered disc. The bottom layer is spongy carbon foam that serves as a flotation device and thermal insulator, which stops the solar energy from dissipating. The top layer is made of graphite flakes that are exfoliated in a microwave. In the microwave, the graphite bubbles up.
When the graphite meets sunlight, it creates hot spots that draw water up through the carbon foam. When water reaches this hot spot, it turns into steam. The efficiency is dependent on the amount of incoming light -- with a solar concentration of 10 times a typical sunny day (this can be done with a lens or reflector), the material converts 85 percent of this light into steam.