Tiny Pen Tip Uses Bacteria as Ink
A new technique lets scientists draws patterns using glowing bacteria. The technique works a little like an old-fashioned pen that requires dipping into ink.
CREDIT: Kzenon | Shutterstock.com
What kind of ink would a microscopic pen use? In a new technique developed by scientists, the ink is comprised of green, glowing, living E. coli bacteria. The new pen-and-ink combo lets researchers make tiny, precise patterns using living bacteria, which may help future researchers make sensors and other small devices powered by microbes, Chemical & Engineering News reported.
To make their fluorescent E. coli pattern, researchers from different institutes in Korea modified a technique called dip-pen nanolithography. The lithography works a bit like a quill pen. Researchers dipped the tip of a high-powered microscope, called an atomic force microscope, into a pot of liquid "ink" containing bacteria. Then the researchers touched the microscope tip onto the surface on which they wanted to draw a pattern.
The pen tip and the ink had to be specially designed to deal with bacteria. The Korean researchers made a unique coating for the microscope tip that traps bacteria and viruses. They also formulated a bacterial "ink" that resists evaporating, so that it won't dry out, killing the bacteria inside.
Previously, other researchers had drawn patterns using "ink" containing DNA, small proteins and other molecules smaller than bacteria. The microscope tip didn't work well with bacteria, however.
The bacterial pen-makers published their work in September in the Journal of the American Chemical Society. The society also publishes Chemical & Engineering News.
Source: Chemical & Engineering News