The Mini Lisa: Scientists 'Paint' Iconic Work on World's Smallest Canvas

You've probably heard of the Mona Lisa, but have you ever heard of the Mini Lisa? Scientists have now created da Vinci's iconic painting on the world's smallest canvas. They've "painted" the portrait on a surface that's approximately 30 microns in width, or one-third the width of a human hair.

Actually creating the image was an impressive technological feat. The scientists used an atomic force microscope and a process known as ThermoChemical NanoLithography (TCNL). Going pixel by pixel, the researchers positioned a heated cantilever at the substrate surface in order to create a series of confined nanoscale chemical reactions. By varying the heat at each location, they could control the number of new molecules that were created. This, in turn, could create different colors. For example, more heat created lighter shades of grey while less heat produced darker shades.

"By tuning the temperature, our team manipulated chemical reactions to yield variations in the molecular concentrations on the nanoscale," said Jennifer Curtis, the study's lead author, in a news release. "The spatial confinement of these reactions provides the precision required to generate complex chemical images like the Mini Lisa."

The project wasn't just to create a small-scale version of the Mona Lisa, though. It was to demonstrate that the technique was possible. The new method could have important implications for the nanomanufacturing of devices. Production of chemical concentration gradients and variations on the sub-micrometer scale are difficult to achieve with other techniques, which is why the new process could be used in the future.

"We envision TCNL will be capable of patterning gradients of other physical or chemical properties, such as conductivity of graphene," said Curtis in a news release. "This technique should enable a wide range of previously inaccessible experiments and applications in fields as diverse as nanoelectronics, optoelectronics and bioengineering."

Although it does have practical applications, though, the new technique also is great for shrinking famous paintings. Besides, it's not every day you get to see a Mini Lisa.

The paper detailing the new findings can be found online here.