A research team at Brigham and Women’s Hospital has created a special, protective coating for small batteries that make them safe enough for even infants to swallow. When a child accidentally ingests a battery the damage done to their little throats and throughout their digestive system can sometimes lead to a painful death. There has been a rise in incidents, and for the first time, a cost-effective fix may actually eliminate the problem, according to their study published in the journal Proceedings of the National Academy of Sciences.

"To date, there has been no innovation to address this issue with small batteries," the study’s coauthor Jeff Karp, BWH Division of Biomedical Engineering in the Department of Medicine, Harvard Medical School, Harvard Stem Cell Institute, said in a press release. "To address this challenge, we sought to develop something that would render the battery inert, specifically when it was outside of a device. This seemed like a tractable problem that we could make significant headway on in a short period of time, just based on our expertise in materials and devices.”

Small, disc-shaped batteries are not only found in many children’s toys, but also hearing aids, remote controls, laser pointers, and musical greeting cards. It’s hard for parents to keep track of all of the places those small chemical button batteries are located, but each year approximately five billion are produced throughout the world. Last year, there were more than 3,000 reported cases of accidental battery ingestion. Karp and his team first realized the problem four years ago and turned to a quantum tunneling coating as a solution — the same stuff that makes touch screens.

"Ingested disc batteries require emergent removal from the esophagus," the study’s coauthor Giovanni Traverso, a gastroenterologist at Massachusetts General Hospital and a researcher at MIT, said in a press release. "The swallowing of these batteries is a gastrointestinal emergency given that tissue damage starts as soon as the battery is in contact with the tissue, generating an electric current and leading to a chemical burn."

Just last month, the autopsy results revealed that a 1-year-old girl died after swallowing a small battery that burned her esophagus while she was playing at home. The battery formed an electric circuit that burned alone the inside of her throat and continued to burn into a neighboring artery. Touch screen materials don’t cause a chemical burn, though. Instead, they allow the electrical current to pass through, and when tested in the gut of living animals, they found batteries encased in the quantum tunneling coating caused no harm. The new technology can be applied to any small disc battery without interrupting the effectiveness.

"The ultimate cost will depend on the exact composition of the material that is used, but for our current formulation, we're talking cents, not dollars," said the study’s coauthor Bryan Laulicht, a postdoctoral fellow at BWH, who also added it would not only reduce injury but also be quite cost-effective.

Source: Karp J, Traverso S, and Langer R. Simple battery armor to protect against gastrointestinal injury from accidental ingestion. Proceedings of the National Academy of Sciences. 2014.