World's smallest Mona Lisa is smaller than a human hair.

And the world's most famous smile is even smaller than that. The world's smallest Mona Lisa has been "painted" by researchers at the Georgia Institute of Technology.

They made Michaleangelo's mysterious lady in the smallest version ever. Ol' Mona is just 30 microns wide.

30 microns, amazingly enough, is only a third as wide as a human hair.

The world's smallest Mona Lisa was painted by a new chemical process, not paint. The process, ThermoChemical NanoLithography (TCNL), "painted" Mona Lisa pixel by pixel.

ThermoChemical NanoLithography (TCNL) captures slight variations in heat to produce slightly lighter or darker shades of gray and dye them-in incredibly small, precise amounts. Each pixel is 125 nanometers.

"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 and an associate professor in the School of Physics.

The resulting Mona Lisa is a little blurry-looking; the process is tricky and sharp edges don't work well. Still, the process may have implications beyond wee portraiture.

"This technique should enable a wide range of previously inaccessible experiments and applications in fields as diverse as nanoelectronics, optoelectronics and bioengineering," Curtis told press.

Her team of researchers is publishing a paper on the process,  "Fabricating Nanoscale Chemical Gradients with ThermoChemical NanoLithography," in the journal Langmuir.