The Lycurgus Cup is, to put it mildly, a rather genius artwork and a perfect example of how well the Romans used nanotechnology to create unique works of art. The 1,600-year-old Roman chalice has a unique chemical property that makes it change from jade green when empty to blood-red when filled with liquid. For centuries, scientists couldn’t figure out what the Romans did until English researchers cleared the mystery in the 1990’s.
[The Romans] impregnated the glass with particles of silver and gold, ground down until they were as small as 50 nanometers in diameter, less than one-thousandth the size of a grain of table salt. The exact mixture of the precious metals suggests the Romans knew what they were doing—“an amazing feat,” says one of the researchers, archaeologist Ian Freestone of University College London.
The ancient nanotech works something like this: When hit with light, electrons belonging to the metal flecks vibrate in ways that alter the color depending on the observer’s position. Gang Logan Liu, an engineer at the University of Illinois at Urbana-Champaign, who has long focused on using nanotechnology to diagnose disease, and his colleagues realized that this effect offered untapped potential. “The Romans knew how to make and use nanoparticles for beautiful art,” Liu says. “We wanted to see if this could have scientific applications.”