Grin and Wear It

Wearable electronics like smartwatches, smart rings, and wireless earbuds have become fixtures in many of our lives over the past few years. The future promises more exotic wearable devices that will attach to different parts of our bodies to track our health, increase our productivity, or entertain us. In most cases, these wearables — when they finally become practical enough to step outside of a research lab — will sit on the surface of our skin.

A group of researchers at MIT CSAIL and Aarhus University just completed some work in which they thought outside the skin’s surface. Specifically, they developed a customizable dental brace that is capable of a wide array of tasks, ranging from collecting health data to serving as an assistive device. Their interactive mouthpiece, called MouthIO, is inexpensive and can be manufactured at home with a 3D printer.

Placing electronics in the mouth is not such an odd idea as it might seem at first. The tongue can be controlled with precision rivaling the fingers — and for many people, their tongue is actually more sensitive than their fingers. These facts make the tongue useful for triggering a discreet input device. A significant amount of important health data can also be captured from this environment by a variety of sensors.

To build MouthIO, one first needs to make a plaster cast of their teeth. A smartphone app like Polycam can then be used (with a compatible device) to perform a 3D scan of the plaster cast. With that information, the model can be modified and prepared for printing with Blender. Modifications may involve the addition of compartments to hide circuit boards and other electronic components. When everything looks good, the mouthpiece can be 3D-printed in a clear dental resin.

The entire do-it-yourself fabrication process takes about two hours to complete, and the materials cost about $15. The costs will naturally vary depending on the choice of hardware components that are installed in the device, however. It is also possible to save some time and use professional-level dental tools to make a MouthIO, but that convenience would come with a larger price tag.

Aside from customizing the electronics, it is also possible to customize the dental brace itself. One could build a mouthpiece that fully covers the teeth, for example. But if the application allows, an “open-bite” design can also be produced, which leaves the tips of the teeth exposed. The open-bite option has the advantage of not causing the wearer to speak with a lisp while the device is inserted.

Early experiments have demonstrated that the device, when equipped with an accelerometer, can detect conditions in which individuals grind their teeth excessively. Other demonstrations have shown that alternative configurations of MouthIO can recognize inputs, like taps, from the tongue. Such a system could be used by individuals with neuromuscular disorders that prevent them from using their arms and hands.

At present, the researchers are running longer-term studies to help them better assess what does, and does not, work well in the present design of MouthIO. They hope that these insights will help them to improve the design in the future — perhaps by using new types of materials or placing the device in different locations within the mouth.