A miniature wearable device that does not require replacement of reagents and recharging will allow monitoring the diet in real time.
Tracking in real time the composition of food and beverages entering the body can facilitate the work of doctors and simplify the conduct of clinical studies, but technically it is quite difficult. Help can developed by researchers from Tufts University (Massachusetts, USA), a miniature sensor that mounts directly to the tooth and wirelessly transmits data to a mobile device – a smartphone, tablet or laptop. The finished prototype analyzes the chemical composition of food and beverages: it estimates the content of glucose, table salt and ethyl alcohol. The article describing the device is being prepared for publication in the journal Advanced Materials.
“Smart” sticker on the tooth is not the first device designed to track the intake of nutrients in the body. In 2014, it was suggested to do this with the help of acoustic sensors and an algorithm, by the sound of chewing recognizing the type and amount of food. Such a wearable device had to take the form of an earpiece; before the device was brought to market, it did not happen. There were also prototypes with chemical sensors, but they were cumbersome and required replacement of the reagents. From its predecessors, the “smart” sticker differs in its compactness and wider range of possibilities.
The authors note that in the future the device can be supplemented with sensors for the presence of other compounds, for example vitamins, trace element salts and toxic substances, as well as temperature, acidity and other physiological indicators.
Dimensions of “smart” stickers are 2х2 mm. The device is flat and flexible and easily adapts to the unevenness of the tooth enamel. Data transmission is not carried out continuously, but only on demand: a small antenna built into the device receives a radio signal from the control device and gives the entire system the command to begin analysis.
The sensor consists of three layers: the central one works like a sponge, and absorbs the analyte; The two upper layers, which are square frames made of gold wire, receive and transmit radio signals. The change in salt composition, sugar content or ethanol changes the conductivity of the central layer and, accordingly, the frequency and length of the wave emitted by the device; for these changes, the algorithm on the mobile device determines which substances came into contact with the sensor.