This tooth-mounted sensor knows what you’ve eaten

Thomas McMullan Read more March 21, 2018

In a world of sensors, it’s easier than ever to monitor the ebbs and flows of our bodies – pinpointing everything from heart rate to blood oxygen levels, from sleep pattern to diet. What information can be gleaned, however, hinges on how easy it is for these devices to track our day-to-day activity.

This tooth-mounted sensor knows what you've eaten

A wrist-bound fitness tracker may be one thing, but scientists at Tufts University are taking bodily insight to a new level thanks to a wireless sensor, mounted directly on a person’s tooth, that can track exactly what has been eaten and drunk.

In a study due to be published in the journal Advanced Materials, the researchers describe tests to develop a sensor that’s able to transmit information about a person’s glucose, salt and alcohol intake. Measuring in at a tiny 2mm x 2mm, the square sensor sticks onto a tooth where it comes into contact with whatever happens to pass beyond a person’s lips.

“Managing and interpreting the data that this device provides can ultimately lead to the identification of patterns of consumption that could have an impact on diet regimens, health management, and maybe make us more aware our nutritional intake,” co-author of the study and Frank C. Doble professor of engineering at Tufts, Fiorenzo Omenetto, told Alphr.

The sensor is made from three layers: a “bioresponsive” layer that absorbs the chemicals being detected, installed between two gold rings that act like a miniature antennae. Taken together, the layers collect and transmit waves in the radiofrequency spectrum, allowing the sensor to wirelessly pass on information to a mobile device about what nutrients are being consumed.

This is made possible due to some clever material science that lets the sensor shift its electrical properties, depending on what chemical its central layer comes into contact with. If, say, the wearer of the sensor is guzzling down a plate of chips, the presence of salt will cause the sensor to absorb and transmit a specific spectrum and intensity of radiofrequency wave.

The device is at an experimental stage, but how could something like this end up being used? “It is always hard to speculate, but one could think that these kinds of devices would have both medical and lifestyle applications,” says Omenetto.

“One could envision nutrition monitoring and relate that to nutrition management. On the other hand, sampling and monitoring analytes in the oral cavity could help in a number of ways: from monitoring dental health to monitoring fatigue through saliva sampling.”

The sensor can currently last a day or two while worn, although future iterations may be able to remain active longer in a person’s mouth. Will glistening teeth sensors ever be in fashion? Perhaps, although another good thing about the tiny sensor is it can be stuck onto pretty much any body part, and be tweaked to pick up all sorts of different chemicals.

“We are really limited only by our creativity,” says Omenetto.

Image: Fiorenzo Omenetto, Tufts University