Scientists at the Georgia Institute of Technology (Georgia Tech) drew a tiny copy of the Mona Lisa they have dubbed the Mini Lisa to demonstrate the power of new nanotechnology tools the group has developed, reports Michelle Starr at CNET.
Size of Mini Lisa
The Mini Lisa is about 30 microns in width, smaller than anything most people ever come into contact with. One micron is a millionth of a meter, but most people find that doesn’t help them make a mental picture. As a comparison, the thickness of a human hair is about 90 microns, so if you’re looking at the side of a hair you have enough room to hang three Mini Lisas side by side.
Aesthetics aside, the point of the project was to demonstrate the precision of something called Thermochemical Nanolithography (TCNL). The basic idea is easy to understand. The scientists covered a surface with a chemical that reacts to heat by changing color, and then carefully applied heat until they had created the image of the Mini Lisa. The breakthrough is in doing the procedure at such small scales. Each pixel in the image was just 125 nanometers across less than a hundredth of the width of the entire image.
Thermochemical Nanolithography a new technology
This new technique is also an advance over other methods because it uses equipment that is fairly commonplace at a nanotechnology lab, even if the rest of us have never heard of it. The chemicals and atomic force microscope that the group used are comparably inexpensive and should open up the door to more experimentation. Reducing costs is also important if innovations that happen within specialized labs are to be scaled up for industrial applications and manufacturing. By reducing the cost and difficulty of creating confined chemical reactions on the nanoscale, TCNL take a step in that direction.
“We envision TCNL will be capable of patterning gradients of other physical or chemical properties,” said lead author associate physics professor Jane Curtis. “This technique should enable a wide range of previously inaccessible experiments and applications.” The findings were published in the article “Fabricating Nanoscale Chemical Gradients with ThermoChemical NanoLithography,” in the journal Langmuir.