Microscopic sensors that can be placed directly on a tooth and communicate with wireless devices, transmitting data on glucose, salt, and alcohol consumption, have been developed by Tufts University School of Engineering researchers.
In a study to be published soon in Advanced Materials, scientists note that future versions of these sensors could allow detection and recording of a wide range of nutrients, chemicals and various body conditions.
Previous wearable devices for diet monitoring suffered from restrictions such as the use of a mouthguard, the existence of cables, the need for frequent replacement of sensors, etc. Tufts engineers wanted a more versatile technology and developed a sensor with a “footprint” of just 2mm x 2mm that can fit and touch on the surface of a tooth. The data is transmitted wirelessly by reacting to an incoming radio frequency signal.
These sensors consist of three layers: A central, “bioreactive” layer that absorbs the nutrients or other chemicals found, and outer layers consisting of two gold rings. Together, these three layers function as a small antenna, collecting and transmitting waves in the radio frequency spectrum.
As an incoming wave strikes the sensor, part of it is canceled and the rest is transmitted back.
It is noteworthy that the sensor can adapt to what comes in: For example, if the core layer comes into contact with salt or ethanol, its electrical properties change, causing the sensor to absorb and transmit a different spectrum of radio frequency waves, varying in intensity . In this way they are detected with measured nutrients and other substances.
“In theory, we can modify the bioreactive layer in these sensors to target other chemicals – we are limited only by our creativity,” says Fiorenzo Omeeto, Ph.D, an equivalent author and professor of engineering at Tufts.