Every year, thousands of children around the world face life-threatening injuries after swallowing a “button” battery—those small, seemingly harmless disc-shaped power sources that can be found in everything from toys and remote controls to hearing aids.
What most parents don’t realize is that these batteries, when ingested, can cause devastating damage in a short amount of time.
In fact, the reactions caused by these batteries inside the body can lead to severe tissue burns, throat damage, and in some cases, even death.
But what if there was a way to make these dangerous batteries safe—even if swallowed?
Researchers from Brigham and Women’s Hospital in the U.S. have developed a new, cutting-edge coating for these batteries that prevents them from becoming deadly once inside the human body.
Their innovation could potentially change the way we think about safety, both in homes and in consumer product design.
A Silent Threat
Button batteries are used in a variety of everyday items, but their small size and shiny appearance make them a magnet for curious young children.
While these devices are generally safe when used correctly, accidents happen—especially when batteries are loose, easily accessible, or incorrectly inserted.
Children who swallow them often don’t immediately show symptoms, but once inside the body, the real danger begins.
When swallowed, these batteries react with saliva or other fluids inside the digestive tract, creating an electric current that generates hydroxide ions.
This reaction, though invisible, is incredibly damaging.
The electric current produced can burn through soft tissue in the throat, esophagus, and stomach, causing irreversible injury.
In some severe cases, the damage is so great that it can lead to life-threatening infections or even death.
It’s not just the risk of harm that makes this issue so serious—it’s the speed with which the damage can occur.
Within just a few hours of ingestion, the tissue can be damaged so severely that it requires immediate medical intervention.
Button batteries have been linked to several fatalities over the years, and the alarming frequency of these incidents has caused growing concern about the safety of such small, powerful power sources.
How Button Batteries Work and Why They’re Dangerous
To fully understand the breakthrough made by the Brigham and Women’s Hospital team, we first need to understand the mechanics behind how button batteries cause such damage.
When these batteries are outside a device, they are inert.
However, when they enter the body, there’s a crucial change in the environment that makes them reactive: the presence of moisture.
Moisture, like the saliva in the mouth or the fluids in the digestive system, creates a conductive environment for the battery to generate an electric current.
This current flows through the metal parts of the battery, creating hydroxide ions as a byproduct.
These ions are highly corrosive and can burn through tissue in a matter of hours.
The pressing issue has always been how to safely disable this current when the battery is outside of a device—without compromising its functionality when it’s in its intended environment.
Enter the groundbreaking discovery by engineers at Brigham and Women’s Hospital.
A Quantum Leap in Technology
The breakthrough came when the researchers decided to focus on how these batteries behave outside of their intended devices.
They observed that when batteries are inside a device, they are usually under light pressure from the device casing or components.
This pressure, which is absent when the battery is swallowed, could be key to solving the issue of battery reactivity.
Taking this insight to the next level, the team developed a new coating for button batteries using a material known as quantum tunneling composite (QTC).
QTC is a rubber-like material used in touch screens, and it’s remarkably versatile.
Under normal conditions, the material doesn’t allow electricity to pass through it—this makes it an ideal insulator.
However, when pressure is applied, the material’s metal particles are brought closer together, allowing an electric current to flow through.
This pressure-triggered switch from an insulator to a conductor is exactly what the team needed.
By applying this material to button batteries, the researchers created a “smart” battery coating that only activates when the battery is under pressure—just like when it’s inside a device.
If swallowed, however, the battery remains inert, preventing any electrical reaction from occurring inside the body.
A Success in Animal Trials
The team didn’t just stop at designing the coating—they needed to test its effectiveness under real-world conditions.
For this, they turned to animal testing.
The researchers coated one side of a button battery with QTC and tested both coated and uncoated batteries in pigs.
The results were nothing short of remarkable.
As predicted, the batteries with the QTC coating caused no harm to the animals’ digestive systems.
The protective coating kept the battery from becoming reactive, preventing any damage to the gut tissue.
On the other hand, the uncoated batteries caused burns and injuries, confirming the hazardous nature of unprotected button batteries.
This test was crucial for validating the coating’s safety and effectiveness, and the results provide a strong foundation for the team’s next steps: making these batteries commercially available.
The breakthrough has the potential to dramatically reduce the number of injuries and fatalities caused by button batteries each year.
Inexpensive, Effective, and Scalable
One of the most exciting aspects of this discovery is the practicality of the QTC material. Unlike many other high-tech solutions, QTC is inexpensive and readily available.
This makes it feasible for battery manufacturers to adopt the coating in their products, creating a safer environment for consumers, particularly parents of young children.
The QTC material is also waterproof, which means it could be used for other applications, such as making weather-resistant batteries in the future.
Jeff Karp, one of the engineers involved in the study, explained that the team’s goal was to develop a solution that was both affordable and easy to implement.
“To date, there has been no innovation to address this issue with small batteries,” Karp said in a press release.
“We sought to develop something that would render the battery inert, specifically when it was outside of a device.”
This solution could become a standard safety feature in all button batteries moving forward, potentially saving lives and sparing families from the heartbreak of such preventable accidents.
Getting the Technology into the Hands of Parents
The team is now focused on taking the next step: ensuring that this technology is brought to market as quickly as possible.
They are working on developing manufacturing processes to produce these new batteries at scale, with the goal of distributing them to consumers.
The potential for this innovation to reach parents, caregivers, and manufacturers is enormous—especially in a world where the dangers of button batteries continue to make headlines.
As we wait for these safer batteries to hit the shelves, it’s worth considering how this breakthrough can be applied to other technologies as well.
For example, could we see other everyday products incorporating pressure-sensitive, safe technologies that prevent hazardous reactions when used incorrectly?
The possibilities for safety-enhancing innovations are limitless.
Button Batteries and Beyond
This discovery by the researchers at Brigham and Women’s Hospital is more than just a solution for a pressing safety issue—it’s a glimpse into a future where consumer products are designed with a deeper understanding of the risks they pose.
The introduction of QTC-coated button batteries could be the first step in creating a broader culture of safety in consumer electronics.
As we’ve seen, small changes in design can lead to large reductions in risk.
By addressing this long-standing problem, the researchers have not only saved lives but also paved the way for future innovations that focus on safety as a core design principle.
This is the kind of forward-thinking approach that could shape the future of technology, ensuring that products not only serve their intended functions but do so with the utmost consideration for the well-being of those who use them.
