Tag Archives: Ghim Wei Ho

Nanoflowers: Microscopic Gardens

Laurie says:

I can’t remember what led me to these exquisite microscopic photographs of nanoflowers. You could put many, many nanoflowers on the head of a pin. This isn’t exactly “how many angels can dance on the head of a pin,” but it definitely exists in the same scale universe. And it would give the angels a beautiful garden to dance in.

I’m always captured by beautiful images from science research.  They show me kinds of beauty that aren’t otherwise available to me.

This research was published in the August, 2004 issue of Nano Letters. When I look more recently there is lots of science information on uses and development, but not much on beauty.  The colors are added for enhancement.
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The quotes are from ScienceCentral.

The next time you buy flowers for that special someone, keep in mind that scientists are constructing tiny bouquets smaller than the width of a human hair. As this ScienceCentral News video explains, these “nanoflowers” could be used as the ultimate waterproof coating.

When people plant gardens, they have to wait for weeks or months to see the beauty of their efforts. But in the lab at the University of Cambridge’s Nanoscience Centre, these nanoflowers — tiny blossoms of silicon carbide one thousand times thinner than the diameter of a human hair — “grow” almost instantly. The “gardeners” are nanotechnologists Mark Welland and Ghim Wei Ho, and they’re using microscopic metal particles as the “seeds”.

The basic principle for growing all of these types of structures is you take a tiny seed particle, and then you expose that particle to a mixture of ‘nutrients,’ just like a seed in a real plant,” explains Welland. “And in this case the nutrients are different mixtures of gases.”

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The researchers begin by heating a tiny droplet of the metal gallium — only a few thousand atoms wide — in a computer-controlled oven. Then they flow methane gas over the droplet, which is attracted to it’s molten surface and induces tiny, rigid rods, or wires, of silicon (what sand is made of) and carbon to grow there. By controlling the temperature and flow of the gas, Ho and Welland can weave the wires into flower-like shapes. As well as gardening, Welland also likens the process to baking a cake.

“If you think of an ordinary oven, and you put a piece of pastry in it and heated it up to 300 degrees Fahrenheit, you might get a banana shape; if you heated it to 400 degrees Fahrenheit you might get a bun; and if you heated it to 500 degrees Fahrenheit you might get a flower,” he says. “That allows us to control very precisely what kind of structure we get. We can literally sit on the computer that controls this oven, and say, ‘we’d like flowers today, please,’ press the buttons, and we have a surface coated in flowers.”

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However, the researchers weren’t expecting such beautiful structures when they began the experiment. According to Welland, it was his student Ho who had the original idea to try out the process with the particular mixture of gas and heat they now use. Forming the rigid nanowires, he says, is already a relatively well-known process, “but when we saw these extraordinary flowerlike structures forming, that was really very exciting for us.