Scientists Paint Mini Mona Lisa on Surface One Third the Width of a Human Hair

Scientists at the Georgia Institute of Technology have painted a mini Mona Lisa on a substrate surface 30 microns in width, which is one third the width of a human hair. The scientists call it the world's smallest canvas. The image was created with an atomic force microscope and a process called ThermoChemical NanoLithography (TCNL). The image below shows an atomic force microscope (AFM) modified with a thermal cantilever. The AFM scanner allows for precise nanoscale positioning while the thermal cantilever induces local nanoscale chemical reactions.

The Georgia Tech researchers positioned a heated cantilever at the substrate surface to create a series of confined nanoscale chemical reactions. By varying only the heat at each location, Ph.D. Candidate Keith Carroll 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 mini Mona Lisa's forehead and hands. Less heat produced the darker shades in her dress and hair. Each pixel in the mini artwork is spaced by 125 nanometers.

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

The research paper, Fabricating Nanoscale Chemical Gradients with ThermoChemical NanoLithography, is published online in the journal Langmuir.

Photos: Georgia Institute of Technology

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