By March 17, 2021, more than 73 million people in the U.S. had received Covid-19 vaccinations. Pharmaceutical companies needed a lot of vials to transport all those doses of medicine. Corning, a glassmaker in upstate New York, supplied them with vials made out of an ultra-tough material called Valor Glass.
The glass used in typical medical vials contains the element boron (B) for added strength. But that material can still crack as bottles clink together on the production line. Even worse, as the glass is melted, boron particles can evaporate—turn from a liquid to a gas—and create tiny flakes of glass that could potentially contaminate medicine.
For years, Corning scientists searched for ways to tackle these problems. “They wanted to figure out what to add to the hot liquid glass that would change its physical properties when it solidified,” says Jane Cook, a materials scientist who worked at Corning.
The researchers ended up swapping boron with aluminum (Al) and submerging vials made from the glass in a hot salt bath. The resulting vials are 10 times stronger than usual—the perfect vessels for safely packaging Covid-19 vaccines.