How shapes self-assemble in nature is a mystery of science yet to be unraveled, but sculpting a miniature flower garden may shed some light on self-assembly and spur innovation in microscopic engineering. The tiny flowers in these images are 50 micrometers large, basically smaller than the width of a human hair, and were all “grown” in a beaker.
To get an idea of their scale, check out the little garden of them on the steps of the Lincoln Memorial on the back of a penny. The research for these flowers, called “Rationally Designed Complex, Hierarchical Microarchitectures,” was published this month in Science. Wim Noorduin, an author on the article and a postdoctoral research fellow at Harvard University, explained to Hyperallergic that “if you look at this in nature, you see all sorts of self-assembling complex shapes in coral reefs and microorganisms. We didn’t want to mimic so much one of these shapes in particular, but wondered if there could be simple chemical process that would give you a wide diversity of shapes.”
In a simple process that Noorduin said you “could do in the kitchen,” a sodium silicate and barium chloride were dissolved in a beaker of water, with the resulting crystals controlled by changes in temperature, carbon dioxide, and the PH level of the solution, leaving white barium carbonate crystals. Basically, by making little changes to the mixture over time, different shapes were “sculpted” with the crystals, in this case delicate little flowers. Self-assembly on the nano-level has long been studied, for example with recent research on self-building flu vaccines. “I think what is unique here is the level of control, that we have and the possibility to continuously control the solution and control the growth of these structures,” Noorduin said.
Next Noorduin said he is working on how to manipulate the changes themselves at a microscopic level, to build even more complicated forms. With that level of complexity, the results could have important nanotechnology applications such as optics and other micro-engineering, and might even produce some really cool micro-art in the process. Below are some more images of the microscopic nanoflowers, which likely double as the world’s tiniest underwater sculptures: