Nanotechnology creates world's smallest version of the Mona Lisa

The world's most famous painting -- the Mona Lisa -- has been recreated on the world's smallest canvas, narrower than a human hair, U.S. researchers report. Scientists at the Georgia Institute of Technology report they've used nanotechnology to "paint" the Mona Lisa on a substrate surface approximately 30 microns in width, about a third the width of a human hair. The technique could potentially be used to achieve nanomanufacturing of devices, they said. The researchers created the image with an atomic force microscope and a process called ThermoChemical NanoLithography, or TCNL, using heat to create a series of confined nanoscale chemical reactions pixel by pixel. By varying only the heat at each location, they controlled the number of new molecules that were created. The greater the heat, the greater the local concentration. More heat produced the lighter shades of gray, as seen on the Mona Lisa's forehead and hands, while less heat produced the darker shades in her dress and hair. Each pixel in the "Mini Lisa" image is spaced by 125 nanometers. "We envision TCNL will be capable of patterning gradients of other physical or chemical properties, such as conductivity of graphene," physics Professor Jennifer Curtis said. "This technique should enable a wide range of previously inaccessible experiments and applications in fields as diverse as nanoelectronics, optoelectronics and bioengineering."