A sponge designed at Massachusetts Institute of Technology converts water into steam by using the sun’s rays. The sponge is made up of a layer of graphite flakes on top and porous carbon foam underneath that acts as an insulator. The sponge floats on top of water and when sun hits the graphite a hotspot is created. Then water is drawn up through the carbon pores and once it reaches the graphite hot spot the water turns into steam. The sponge is able to convert 85% of solar energy into steam. The steam could for instance be used for desalination of water, the MIT team says.