Washington, Aug 7 (): American scientists have created a mini version of the famous painting of Leonardo da Vinci’s Mona Lisa on the world’s smallest canvas, which measures just 30 microns in width, the surface one-third the width of a human hair.
The team created this mini painting ‘Mona Lisa,’ by using an atomic force microscope and a process known as Thermo Chemical Nano Lithography (TCNL).
The team used a heated cantilever, a small device that can exactly apply heat to a surface. Using the cantilever the researchers prompted heat-based chemical reactions on a surface. When more heat was applied, the picture got a darker shade of grey in that area. They worked pixel by pixel, to apply the right amount of heat to get the colour of grey they desired.
The researchers applied different amounts of heat at different spots, until they created a black and white version of da Vinci’s famed painting.
Jennifer Curtis, lead author and an associate professor in the School of Physics said in a statement by tuning the temperature, their team manipulated chemical reactions to yield variations in the molecular concentrations on the Nano scale. Each pixel is spaced by 125 nanometres.
Production of chemical concentration gradients and variations on the sub-micrometre scale are difficult to achieve with other techniques, despite a wide range of applications the process could allow.
Curtis said that this technique should enable a wide range of previously inaccessible applications and experiments and in fields as diverse as nano electronics, optoelectronics and bioengineering.
Another advantage is that atomic force microscopes are fairly common and the thermal control is relatively straightforward, making the method accessible to both industrial and academic laboratories.
The researcher said that the spatial limitation of these reactions provides the exactness required to generate complex chemical images like the Mini Lisa.
As the technique offers high spatial resolutions at a speed faster than other existing methods, even with a single cantilever, Professor Curtis is hopeful that TCNL will provide the choice of Nano scale printing integrated with the fabrication of large quantities of surfaces and the materials with dimensions more than one billion times larger than the TCNL features themselves.