Wireless tooth tattoo can detect bad bacteria

Researchers at Princeton say the sensor adheres to dental enamel and might one day continuously monitor a patient's health.

Elizabeth Armstrong Moore
Elizabeth Armstrong Moore is based in Portland, Oregon, and has written for Wired, The Christian Science Monitor, and public radio. Her semi-obscure hobbies include climbing, billiards, board games that take up a lot of space, and piano.
Elizabeth Armstrong Moore
2 min read

Some tech just sounds too good to be true. A removable, wireless sensor that adheres to dental enamel and can detect trace amounts of harmful bacteria just might fall into the too-much-information category for the squeamish among us.

On a cow's tooth, the sensor can detect bacteria and send a signal to a nearby receiver. Michael McAlpine/Princeton University

But the silk, gold, and graphene-based sensor that looks a bit like a temporary tattoo could play a key role in detecting and treating various diseases and conditions, the developers at Princeton University say.

"This is a real-time, wireless response from a sensor that can be directly interfaced with a variety of biomaterials," principal investigator Michael McAlpine, an assistant professor of mechanical and aerospace engineering, said in a school news release. "In principle, the graphene can be...configured to detect DNA or certain viruses."

For the team's study, published in the journal Nature Communications, the sensor was affixed to a cow's tooth and tailored to detect a sample of bacteria described as causing surgical infections and leading to stomach ulcers.

The major advance, the researchers say, is using graphene with a biocompatible base -- in this instance silk -- instead of silicon. Not only is silk easier to interface on a body part, and thus more comfortable for the user, but it is also soluble, so it can wash away with water or be dissolved by enzymes and leave the graphene and antenna in place.

The major challenge, they add, is getting the antenna that transmits the data small enough to be used on a human (instead of a cow's) tooth. The researchers say they also need to better understand how long the adhesion between the enamel and graphene sensor will last, not to mention how well the system will weather the storm of the mouth -- from chewing to brushing.

Still, they are optimistic that they've developed the early iteration of a wireless tattoo-like device that will live on a human tooth for a set period of time and wirelessly monitor many aspects of the wearer's health -- or the health of someone who just happens to come within, shall we say, close quarters.