High-tech threads sense how and when the wearer moves

Tufts University engineers have developed a flexible thread-based sensor that can measure neck movement and provide data on direction, angle of rotation, and degree of displacement of the head. Researchers say the breakthrough has the potential to be used as a thin tattoo-like patch that could measure athletic performance, monitor worker or driver fatigue, assist with physical therapy, enhance VR games, and improve computer-generated imagery for cinematographers. The thread-based sensors can be woven directly into textiles.The researchers placed two of the threads in an X-pattern on the back of the subject's neck. Threads are coated with an electrically conducting carbon-based ink. The sensors detect motion when the threads bend, creating strain that changes the way they conduct electricity. When the subject performs a series of head movements, the wire sends signals to a small Bluetooth module that can transmit the data wirelessly to a smartphone or PC for analysis.

By analyzing the data, machine learning algorithms interpret the signals and translate them into quantitive head movements in real-time. The sensors in the algorithm are 93 percent accurate. The wireless sensors allow the tracking of motion without interference from wires, bulky devices, or limiting conditions such as the requirement for cameras. Subjects also don't have to be confined to a room or laboratory for measurement.

Researchers say the algorithms have to be specialized for each location of the body, but the sensors could measure movement in other limbs. The tech could be used to create skin patches or form-fitting clothing containing threads used to track movement in settings where measurements are most relevant, like the field, workplace, or classroom.

The researchers believe that for the athletic field, their threat-based sensor approach could be a game-changer. Tattoo-like patches can be placed on different joints allowing athletes to track their physical movement or form.