Researchers at the Tufts University have developed new, miniature sensors, that when mounted directly on a tooth and communicating wirelessly with a mobile device, can transmit information when consuming glucose, salt and alcohol.
The researchers note that future adaptations of these sensors could enable the detection and recording of a wide range of nutrients, chemicals and physiological states.
While previous wearable devices for monitoring dietary intake suffered from limitations such as requiring the use of a mouth guard, bulky wiring, or replacement of sensors, Tufts engineers developed a 2mm x 2mm sensor. The new divice can flexibly bond to the surface of a tooth. the sensors transmit their data wirelessly in response to an incoming radiofrequency signal.
The sensors are made up of three sandwiched layers: a central “bioresponsive” layer that absorbs the nutrient or other chemicals to be detected, and outer layers consisting of two square-shaped gold rings. Together, the three layers act like a tiny antenna, collecting and transmitting waves in the radiofrequency spectrum. As an incoming wave hits the sensor, some of it is cancelled out and the rest transmitted back, just like a patch of blue paint absorbs redder wavelengths and reflects the blue back to our eyes.
The sensor, however, can change its color acordingly to the material it is aim to derect. For example, if the central layer takes on salt, or ethanol, its causing the sensor to absorb and transmit a different spectrum of radiofrequency waves, with varying intensity. That is how nutrients and other analytes can be detected and measured.
“In theory we can modify the bioresponsive layer in these sensors to target other chemicals – we are really limited only by our creativity,” said authors Fiorenzo Omenetto, Ph.D., and Prof. Frank C. Doble. “We have extended common RFID [radiofrequency ID] technology to a sensor package that can dynamically read and transmit information on its environment, whether it is affixed to a tooth, to skin, or any other surface.”