American engineers have developed a small sensor that, when placed directly on a tooth, analyzes in real time the glucose, salt and alcohol consumption of a person.
Researcher Fiorenzo Omenetto and his colleagues at the Tuts University School of Engineering say that their device can accurately measure the amount of these three substances that a person consumes, and thus better understand their eating habits.
A future adaptation of this sensor will detect a wider range of nutrients and chemicals and may even provide information on the physiological state of a person, say its inventors.
Real-time knowledge of what a person consumes can be important for medical monitoring or clinical studies. This task is not easy, however.
There are other portable devices for monitoring food intake, but these have several limitations, such as the use of a mouth guard or cumbersome wiring. They must also be frequently changed because they degrade quickly.
A tiny antenna
The technology used in the new sensor of only 2 mm by 2 mm allows it to adhere to the irregular surface of a tooth.
It collects information a bit like a “toll station on a highway, then transmits it using a radio frequency signal.”
The sensor is composed of three layers:
a central layer (sandwiched) of bioreactive materials absorbing nutrients or other chemicals to be detected;
two outer layers each consisting of a square gold ring.
Together, these three layers act as a tiny antenna, collecting and transmitting information.
Thus, if the core layer absorbs salt or ethanol, its electrical properties will shift, and the information that the sensor will detect will be transmitted in a specific spectrum of radio waves, with varying intensity.
This is how nutrients can be detected and measured and other tests can be performed.
“In theory, we can change the core layer of the sensor to target other chemicals. Our creativity is our only limit! Says Fiorenzo Omenetto.
The details of this invention are described in the journal Advanced Materials.