http://www.digitaljournal.com/life/health/technology-designed-to-track-what-you-eat/article/518151

Technology designed to track what you eat

Posted Mar 23, 2018 by Tim Sandle
Scientists have developed tiny tooth-mounted sensors that can track what a person eats. The aim is to use wireless real-time monitoring to increase medical understanding between diet and health.
The 2x2 mm sensor monitors ingested fluids and transmits information wirelessly.
The 2x2 mm sensor monitors ingested fluids and transmits information wirelessly.
Fio Omenetto, Ph.D., Tufts University
Technologists, from Tufts University School of Engineering, have engineered miniaturized sensors designed to fit onto a tooth; the sensors measure 2 millimeters by 2 millimeters. When a sensor is positioned directly onto a tooth it can communicate wirelessly to mobile device. The type of information that can then be transmitted includes levels of glucose, salt and alcohol intake.
The long-term aim is to use the technology to enable the detection and recording of a wide range of nutrients and chemicals consumed by a person, and to help assess the physiological state of the individual. This will allow for better data to be collected for research and even to help to control a person's diet.
The complexities with the development were with making the wireless technology work and with creating a sensor that could flexibly conform and bond to the irregular surface of a tooth. Each sensor is composed of three layers. The first is a central "bioresponsive" layer that absorbs the nutrient or other chemicals to be detected,; the other two are outer layers consisting of two square-shaped gold rings. Each device functions as a miniature antenna, serving to collect and transmit waves in the radiofrequency spectrum to a mobile device.
Commenting on the development, lead researcher Fiorenzo Omenetto told Medical News Today: ""In theory we can modify the bioresponsive layer in these sensors to target other chemicals -- we are really limited only by our creativity. 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."
Details of the technology have been published in the journal Advanced Materials, with the research paper titled "Functional, RF-trilayer sensors for tooth-mounted, wireless monitoring of the oral cavity and food consumption."