Microscopic crystal 'flowers' build themselves in a Harvard lab
Researchers formed hierarchically complex structures by controlling the growth of crystals in a solution. Here, a coral shape was nucleated on top of a spiral. (The scanning electron microscope view is false-colored, but represents the actual color of the structure.)
Imagine peering into a microscope and finding yourself in a garden. That's the case at Harvard School of Engineering and Applied Sciences, where researchers have found a way to shape microscopic crystals into complex and often beautiful structures. Inspired by coral reefs, seashells and other naturally occurring complex mineral structures, postdoctoral fellow Wim L. Noorduin and Harvard colleagues have been researching ways to create similar designs. These "flowers" were created by mixing barium chloride and sodium silicate, also known as waterglass, in a beaker of water. The resulting reaction combines with carbon dioxide in the air to create crystals made of barium carbonate in the water. "When you look through the electron microscope, it really feels a bit like you’re diving in the ocean, seeing huge fields of coral and sponges … Sometimes I forget to take images because it's so nice to explore," Noorduin said in Harvard's press release. Noorduin's findings follow a similar discovery from Harvard biologist Howard Berg, who found that certain bacterial colonies take intricate geometric shapes in response to concentrations of chemicals around them.
