Ingestible Button Batteries

Applications

This technology can be used to produce safer button batteries for use in consumer electronics and children’s toys.

Problem Addressed

Every year in the United States, the accidental ingestion of button batteries impacts thousands of children as well as a growing number of senior citizens and family pets. These incidents contribute to approximately 4,000 emergency room visits annually.  

Ingested batteries generate external electrolytic current and produce hydroxide ions which cause tissue damage. Additionally, the short circuit current in conductive bodily fluids damages the battery gasket, releasing toxic metals such as cadmium, lead, mercury and lithium. Once the batteries reach the stomach, corrosive and conductive gastrointestinal fluids further facilitate the release of the harmful battery contents, which poses both acute and long-term health risks associated with heavy metal ingestion.

The most severe damage occurs when the battery is lodged in the esophagus, resulting in tissue damage that may cause vocal cord paralysis, esophageal strictures, esophageal perforation, tracheoesophageal fistula, aortoesophageal fistula, or even death.

The Consumer Product Safety Improvement Act of 2008 and the Button Cell Battery Safety Act of 2011 were implemented to address this mounting health concern. Although some progress has been made by these safety regulations, improving the safety of batteries themselves has not been addressed. Hence, there is a need for a product that can circumvent the harmful consequences of ingesting button batteries.

Technology

This invention presents a button battery coating consisting of a waterproof, pressure-sensitive quantum tunneling composite (QTC). It is non-conductive when immersed in conductive fluid environments, and it allows the battery to conduct normally when pressed upon by the electrode in a battery housing.

Standard button batteries in conductive fluids form electrolytic currents that cause tissue damage and breakdown of the gasket separating the anode and cathode. Within hours of immersion, they begin to release harmful battery contents. In contrast, quantum tunneling composite coated (QTCC) button batteries do not result in damage or current loss. When immersed in a simulated intestinal environment, QTCC button batteries do not produce electrolysis and do not release the harmful battery contents. Hence, these QTCC button batteries, when swallowed, prevent the external current responsible for tissue injury and the leakage of harmful battery contents. 

Electromechanical characterization demonstrates that QTCC button batteries remain sealed from contact with conductive bodily fluids and require approximately twice the pressure supplied by the adult esophagus and gastrointestinal tract to conduct.  QTCC button batteries should drastically lesson or even prevent the button battery from short circuiting after ingestion. 

Advantages

  • Can power most battery-operated devices without modification of standard battery housings 
  • Markedly reduces the ingestion hazard of button batteries