An old story about glass goes something like this: A glassmaker, presenting his wares to the Roman emperor Tiberius, handed over a bowl for inspection. After studying it, Tiberius returned the bowl to the man, who promptly hurled it to the ground. Rather than smash to pieces, the glass merely dented; it had been fashioned from a substance that the ancients called vitrum flexile. Amazed, Tiberius asked if anyone else knew how to make it. When the artisan said no, the emperor—fearing that such an invention would devalue treasuries filled with gold and silver—had him executed.
The story was, as the historian Pliny wrote, “more widely spread than well authenticated.” But it captures an aspiration nearly as old as glass itself: to create resilience in the fragile substance that results when hot silica fuses with other minerals. That aspiration now carries special importance. After many months in which the COVID-19 pandemic has brought misery to much of the world, new vaccines will soon be ready for distribution. Getting them to people who need them will require more than a billion vials to be manufactured, filled, and shipped, at top speed and in some cases under extreme stress. (Pfizer’s vaccine must be kept colder than ninety degrees below zero.) Under any circumstances, putting medicine into glass is a tricky business. Standard medical vials—made of borosilicate—often break as they’re filled, and just one damaged vial can ruin a batch of doses and stop a production line.
These photographs, taken by Christopher Payne at two Corning facilities in upstate New York, tell the story of an alternative to borosilicate, called Valor Glass, and its use in the effort to deliver COVID-19 vaccines. The development of Valor Glass began in 2011, when Corning’s researchers were working to reinvent medical vials, which had not changed substantially for a century. Using platinum-lined ceramic crucibles, heated to more than a thousand degrees, they spent hundreds of hours combining silica with new ingredients. As Robert Schaut, one of the project’s leaders, said, “The periodic table is our toolbox.” They found that, by adding alumina and removing boron, they could make the glass far more resistant to degradation, and therefore less likely to leach contaminants into the contents. Other innovations came later, and the vials went on the market in 2017. This June, the federal government granted Corning more than two hundred million dollars to produce them for COVID vaccines.
Corning’s manufacturing process, which Payne documents with an architect’s sensitivity to form, begins with cylindrical machines called converters. They cut and shape tubes of Valor Glass into vials, which are then submerged in a molten-salt bath. Potassium atoms in the hot mixture swap with smaller sodium atoms embedded in the surface of the glass, creating tension and therefore toughness. (Corning first developed this process for Gorilla Glass, which is used in iPhones and other electronic devices; a vial fortified in this way can withstand as much as a thousand pounds of force.) Afterward, the glass is rinsed, and the exterior is given a polymer coating, so that bottles don’t grind against one another on a filling line, generating glass dust that can ruin doses. All this work is being conducted under conditions of severe urgency. Corning’s facility is running around the clock. “Glass is used to protect our most valuable liquids,” Schaut said. “It has an aura of protection.”
By the end of the year, the machines in these images will have produced enough vials to deliver more than a hundred million doses of COVID-19 vaccines, but Corning’s production is merely one part of a larger effort. SiO2 Materials Science, a company in Alabama, is manufacturing another alternative to borosilicate vials. The makers of the standard product have been ramping up operations, too. The demand calls for everything. As the chief executive of AstraZeneca, one of the companies racing to produce a vaccine, warned, early in the pandemic, “There’s not enough vials in the world.”
—Raffi Khatchadourian
