A clip-on sensor to turn face mask into smart monitoring device

The smart sensor platform can sense a user’s real-time respiration rate, heart rate and mask wear time. It uses a tiny magnet to attach to any N95, cloth or surgical face mask.

Inside of a mask with FaceBit device.

Since the onset of the COVID-19 pandemic, face mask use has become a common practice with people around the globe wearing them for long hours each day. Now, a team of researchers have developed a clip-on sensor that can turn any face mask into a smart monitoring device.

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The smart sensor platform that the researchers at Northwestern University are calling a “Fitbit for the face”, can sense a user’s real-time respiration rate, heart rate and mask wear time. It uses a tiny magnet to attach to any N95, cloth or surgical face mask.

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‘FaceBit’ wirelessly transmits real-time data to a smartphone app, which can alert the user when issues, such as elevated heart rate or a leak in the mask, arise.

It is powered by a tiny battery and designed to harvest energy from ambient sources, including the force of the user’s breathing, motion and heat from a user’s breath as well as from the sun, according to the researchers.

The team found that FaceBit’s battery lasted longer than 11 days between charges, and its accuracy was similar to clinical-grade devices. They have evaluated the device on volunteers in real-world scenarios, however, it still needs to undergo clinical trials and validation, the university noted.

Additionally, the sensor may be able to replace tests like a 20-minute fit test that health care workers periodically undergo to ensure their N95 masks are properly sealed to their faces.

Although, according to the team, FaceBit cannot yet replace this process, but can ensure the mask retains proper fit between testing events. If the mask becomes loose, it can alert the wearer.

The research team hopes to make the device completely battery-free, with harvested thermal and kinetic energy solely powering the device in the future. They have detailed their work in an article titled ‘FaceBit: Smart Face Masks Platform,’ published in the journal Proceedings of the ACM on Interactive, Mobile, Wearable and Ubiquitous Technologies .