Scientists at the University of Sheffield have developed a consistent recipe for reproducing the green-and-red optical effect of the ancient Roman Lycurgus Cup. Their work uses carefully controlled amounts of silver and gold nanoparticles in glass, and has led to a modern sculpture by British glass artist Elliot Walker.
An elusive recipe
In 2020, Dutch researchers reproduced the Lycurgus Cup’s green-red dichroism effect in 3D-printable nanocomposites by embedding appropriately sized and shaped silver and gold nanoparticles. However, no one had yet developed a consistent and reproducible recipe for making the effect in glass.
Lisa Holland and Caroline Jackson of the University of Sheffield worked together to solve the problem. Jackson is an expert in Roman glass. The researchers experimented with different furnace types, materials and oxygen levels, and at one point even added sugar to the mixture.
“We knew that manufacturing this type of glass was likely to be a complex task, as it involved not simply adding nanoparticles to the glass,” Holland said. “I’ve been studying and working with glass for over 25 years, so I used the knowledge and experience I’ve gained, combined with modern scientific understanding of what I was trying to achieve. But if a Roman saw me experimenting, he would probably laugh and ask, ‘Why doesn’t she know how to make this?’”
The experiments succeeded when Holland found a mixture that produced the desired optical effect: the glass appears green in reflected light and red when illuminated from behind.
Holland’s early glasswork was featured in Lightfest, part of Molecular Photonic Breadboards, a UK project focused on designing new materials that harness light for sustainable technology. Project leaders then turned to British glass artist Elliot Walker, the season 2 winner of Netflix’s Blown Away competition, to create a modern sculpture inspired by the Lycurgus Cup.
A modern interpretation
“It is very rare to have the opportunity to work with glass that has been developed from ancient mixtures and recipes, but it is always very exciting,” Walker said. “You can really see how glassmakers of the past have adapted to this kind of glass. It’s like shaking hands.”
“I wanted to keep this sculpture in a very classical form and tell the original story of Lycurgus depicted on the cup, but I needed a blown element in this to really show the dichroic glass. This piece is a fusion of the Lycurgus story and the Farnese Atlas sculpture, with the earth being replaced by the cup.”
The public will be able to see Walker’s sculpture in person when it goes on display at the Millennium Gallery next month during the University of Sheffield’s Festival of the Mind. It will then be permanently displayed at the university’s Turner Museum of Glass.
Source: arstechnica.com
