Engineers at Northwestern University (USA) have developed a prototype of smart glasses that draw energy from facial movements - blinking, raising the eyebrows, and clenching the jaw. The device, called GlassTENG, is equipped with three flexible sensors that convert mechanical energy into electricity.
The technology is based on the triboelectric effect - the phenomenon of static electricity familiar to everyone, in which friction or separation of two different materials causes a transfer of electrons and produces a brief charge. Each sensor consists of layers that compress and decompress when the face moves, generating voltage. For example, blinking presses on one sensor, jaw clenching activates another, and an artery pulse activates the third.
The sensors are mounted at three points on the frame: near the bridge of the nose (capturing pulse, blinking and eyebrow movement), at the temple (recording the superficial temporal artery and jaw movements), and closer to the ear (registering chewing and clenching). The signal strength differs: an artery pulse produces about 50-100 millivolts, blinking and eyebrow raising about 200-500 millivolts, and strong jaw movements up to 1.5 volts. These differences make it possible to recognize different activities by their electrical "signatures".
The trials involved 20 volunteers. They performed six actions: blinking, raising their eyebrows, clenching their teeth, tapping their teeth, eating and talking. Machine learning algorithms analyzed the signals and determined what the person was doing. The average accuracy across all six activities was 93.8%, with teeth tapping recognized with 99% accuracy and jaw clenching with 96%.
The three sensors together consume only 4.1 microwatts - orders of magnitude less than many traditional sensors. Data is transmitted via Bluetooth to a smartphone or tablet. In the future, the researchers hope to add computing to the device so that it could, for example, immediately warn the user about jaw clenching.
The authors believe that such glasses will help unobtrusively track cardiovascular indicators, bruxism (involuntary jaw clenching and teeth grinding), fatigue and eating behavior throughout the day - without bulky batteries and the need for regular recharging. "Half the population already wears glasses," notes the head of the work, Nivedita Arora. "We can turn them into a wearable device without requiring people to change their habits."
The results were published in the proceedings of the ACM International Symposium on Wearable Computers 2026. So far this is a laboratory prototype, and no timeline for the product's appearance on the market has been announced.