While it may be true that “you are what you eat,” it still remains difficult to track your intake accurately. Anyone who has spent time paging through a calorie booklet of different foods knows how frustrating it can be, and that’s even without struggling with portion sizes. What if there was a convenient way to track what you eat and drink?

Researchers at Tufts University have developed a tiny wireless sensor that can be mounted to a tooth in a subject’s mouth. The entire device is just 2 mm square (less than one tenth of an inch) and is flexible so that it can conform to the curved shape of a tooth. A central bioresponsive layer detects the target nutrient or other chemical, and the surrounding gold layers act as antennas. When activated by a radio wave — the same used by RFID devices — the data reflected back by the sensor varies depending on the amount of target substance is present. By modifying the middle layer, the researchers can detect a wide range of different substances.

The sensors could also be mounted on the skin or other surfaces of interest. The fact that it is wireless and is energized by external radio waves means that there is no need for batteries or recharging. The result is a device that could be “set it and forget it” while a remote monitor gathers the data. This could lead to a variety of applications that would make it easier for individuals and their healthcare providers to monitor their intake of various nutrients and chemicals, which could lead to long-term gains in terms of weight management or chronic disease control.