Scientists at Georgia Tech have created a Mona Lisa reproduction about 30 microns wide, or about one-third the width of a human hair.
The team also created a few microscopic Ansel Adams landscape reproductions as well, but copyright issues prevented the scientists from sharing those with the rest of us. Although you can find one of them -- a reproduction of a 1932 picture of a rose with driftwood -- in a study about the process that created these images in the journal Langmuir.
To create the tiny images, the scientists used a standard atomic force microscope and a tiny cantilever with a tiny needle attached to it -- which could be heated to different temperatures.
The cantilever went pixel by pixel over a piece of substrate. At each stop the cantilever was heated to a different temperature, which caused a varying amount of a chemical reaction on the tiny canvas. A hotter needle created a lighter pixel, a cooler needle a darker pixel in the final product.
Jennifer Curtis, a professor at Georgia Tech and the lead author of the paper, said the entire process was automated, so no one had to move the needle nanometer by nanometer to create the image.
"My graduate student Keith Carroll streamlined everything," she said. "He can take any picture you want, and create a corresponding temperature map and send it to the machine to draw on the nano-scale."
Curtis said the study showed it was possible not only to put molecules on a nano-surface, but to vary how many of them are actually there.
"Before, it was very binary -- something was there or nothing was there -- but this is like using a pencil instead of a marker," she said. "Now we can do shading, and it increases the sophistication of anything you can make."
Curtis also said her graduate student created the mini-Mona Lisa on a dare.