|Lycurgus Cup 4th Century CE|
Images Courtesy of the British Museum
The Lycurgus Cup is a Roman glass cage cup, or diatretum, made of dichroic glass. This means that the properties of the glass allow it to change color depending from which angle light is shown through. If lit from behind the glass turns red and green if lit from the front. The cup depicts the ancient Greek myth of the Thracian King Lycurgus. Lycurgus was fated a horrible death by Dionysus who cursed him for banning his religion and imprisoning his followers. There are several variation of this myth, but the reference seen on the cup ( Lycurgus trapped in wine vines) is not common variation. However, there is a satyr and a figure believed to be Dionysus (due to panther [Dionysus' patron animal] and the thyrsus [a staff with a pine cone tip carried by his followers]) who are expressing angry gestures.
The Lycurgus Cup is a rare item from history, whose use is still unknown and highly speculated. It has been thought to have been used in the rites of Bacchus (Dionysus Roman counterpart). However, this can not be proved. Coincidentally, the Historia Augusta records the gift of two dichroic cups from Emperor Hadrian to his brother-in-law Servianus via a letter. Perhaps, this may have been one of them.
The color changing ability of the glass is due the size of metal flecks and how their electrons vibrate that alters the color. Gang Logan Liu, an engineer at the
that when various liquids filled the cup it would change the vibration of the
electron and thus the color. Thus, he argued that the Lycurgus Cup's phenomenon
was very similar to a home pregnancy test, which uses a nano-based technology
to turn a white line pink at the presence of HCG in urine. So, researchers
began to formulate an experiment to test this hypothesis. University
Due to the fact that the Lycurgus Cup is a prized and unique artifact, researcher were unable to fill the cup itself. However, they created billions of wells (about the size of postage stamp) and sprayed them with a gold and silver nanoparticles. Thus, they created essential tiny version of the Lycurgus Cup. Then, they continued with experiment by filling these wells with different types of liquids. The result was as predicted and the colors ranged from light green for water to red for oil. This "well" prototype was 100 times more sensitive to the differing salt levels of tested liquids than current sensor used for similar testing.
Liu was hopefully to see if the Roman's nanotechnology of gold-silver alloy particles could have current science applications. This experiment proved that one day this technology may make its way to handheld devices for detecting pathogens in salvia or urine.