Experts ‘paint’ world’s smallest Mona Lisa

Mini Lisa! Scientists have “painted” a mini version of Leonardo da Vinci’s masterpiece Mona Lisa on the world’s smallest canvas, a surface one-third the width of a human hair. Researchers at the Geo-rgia Institute of Techn-ology “painted” the wor-ld’s most famous painting Mona Lisa on a substrate surface approximately 30 microns in width.

The creation, the “Mini Lisa,” demonstrates a technique that could potentially be used to achieve nanomanufacturing of devices because the team was able to vary the surface concentration of molecules on such short-length scales.

The image was created with an atomic force microscope and a process called ThermoChemical NanoLithography (TCNL). Going pixel by pixel, 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, 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 Lisa’s forehead and hands. Less heat produced the darker shades in her dress and hair seen when the molecular canvas is visualised using fluorescent dye. Each pixel is spaced by 125 nanometres.

“By tuning the temperature, our team manipulated chemical reactions to yield variations in the molecular concentrations on the nanoscale,” said Jennifer Curtis, study’s lead author. “The spatial confinement of these reactions provides the precision required to generate complex chemical images like the Mini Lisa,” said Curtis. Production of chemical concentration gradients and variations on the sub-micrometre scale are difficult to ach-ieve with other techniques, despite a wide ra-nge of applications the pr-ocess could allow.

Source: http://tinyurl.com/mnlus93