A flower fit for a Lilliputian maiden, this microscopic «rose» was grown in a laboratory at Harvard University using a solution of chemicals and minerals.
«[This] is the very first image I shot,» said Wim Noorduin, a researcher specializing in crystal growth at Harvard.
Building micro- and nano-size particles—some much smaller than the width of a human hair—is a huge field, since they have potential uses in optics and engineering, said Noorduin.
Getting structures to self-assemble or grow from a solution of chemicals is relatively straightforward: Confectioners have done this for years when growing rock candy.
But the trick with Noorduin’s technique, which he has taken years to perfect, is he can control the shapes of the structures as they’re growing by changing the temperature, pH, and carbon dioxide content of his chemical solutions.
Researchers chose to create «flowers,» «stems,» and «vases» because they were the easiest shapes to start with.
«You can collaborate with the process as it’s [happening],» said Noorduin, who published his research May 16 in the journal Science.
All you need is a beaker of water mixed with barium salts and sodium silicate, a flat plate to place inside the beaker for the flowers to grow on, and a lid.
When the barium salt and sodium silicate solution in the beaker is exposed to carbon dioxide, stems and flowers (pictured) start to grow on a flat metal plate.
By controlling the amount of carbon dioxide dissolving into the beaker, how acidic or basic the solution becomes, and the temperature, Noorduin can produce shapes that look like vases, stems, spirals, flowers, or leaves.
By simply sliding a lid on and off the beaker of chemicals, Noorduin can control how much carbon dioxide enters the water. This allows him to dictate the self-assembly of these minerals so precisely, he can grow shapes right on top of each other.
Above, he’s grown green-colored vases inside of the red «coral» structures, and capped the sculpture with purple flowers.
By growing his flowers on a metal plate placed inside the beaker, Noorduin can sculpt a lot of them at once. This can yield beautiful fields of microscopic structures.
«This is one thing I must say that I like the most,» Noorduin said. «If you look under a microscope, these fields are really large. You can get completely lost in this whole world on the slide.»
Image courtesy: Wim Noorduin (first three pictures), Laura Hendriks and Wim Noorduin (last picture)