Solar sponge: The top layer of graphite soaks up the sun's energy in tiny holes. When drops of liquid fill the holes, the water quickly evaporates. (The beaker looks hot, but the water below the sponge is cool as a cucumber.) Courtesy of George Ni/MIT hide caption

itoggle caption Courtesy of George Ni/MIT

Nanoflowers, each smaller than the thickness of a dollar bill, sprout up spontaneously on a surface dipped in salts and silicon. Courtesy of Wim Noorduin/Harvard University hide caption

itoggle caption Courtesy of Wim Noorduin/Harvard University