Truth, Inspiration, Hope.

Researchers Develop FaceBit, a Wireless Sensor for Masks and Medical Respirators

Victor Westerkamp
Victor resides in the Netherlands and writes about freedom and governmental and social changes to the democratic form of nations.
Published: February 8, 2022
Researchers from Northwest University developed the FaceBit, a quarter-sized sensor that affixed to masks and respirators with a magnet to measure fit, heart rate, and respiration.
A test user wears a prototype of a wired version of FaceBit, a quarter-sized sensor meant to be affixed to N95 medical respirators and cloth masks alike to measure data such as heart rate, respiration, and mask fit. (Image: Research Article Screenshot)

Researchers have developed a smart sensor that can be applied to masks that monitors a user’s breath rate, heart rate, and other health metrics—but fails to address essential factors relevant in the Coronavirus Disease 2019 (COVID-19) pandemic climate, such as oxygen deprivation or efficacy against viruses.

“We wanted to design an intelligent face mask for health care professionals that does not need to be inconveniently plugged in during the middle of a shift,” the research head Josiah Hester, an Assistant Professor, said in a Northwestern University press release.


The “FaceBit,” as the invention has been catchily-dubbed, is a relatively bulky chip to dangle on your face at the size of a quarter. The device attaches using a magnet to any mask, specifically professional-grade N95, KF94, or the lower-standard Chinese-made KN95 respirators.


The battery derives part of its energy supply from movements taken by its user. The rest comes from sunlight and the warmth of the user’s breath, and is promoted as having a runtime of at least 11 days before needing to be plugged in.

“We augmented the battery’s energy with energy harvesting from various sources, which means that you can wear the mask for a week or two without having to charge or replace the battery,” the Assistant Professor said.

But even if you manage to keep your battery running for two weeks, manufacturers’ guidelines nonetheless prescribe that N95 respirators be replaced after three to four hours weartime, at a maximum, according to a September article by KSL News Radio. So you must refit your device regularly, anyhow.

“If you wear a mask for 12 hours or longer, sometimes your face can become numb,” Hester continued, in an apparent disregard of sanitary masking guidelines.

Monitoring and feedback

“You might not even realize that your mask is loose because you cannot feel it, or you are too burnt out to notice,” Hester continued. “We can approximate the fit-testing process by measuring mask resistance. If we see a sudden dip in resistance, that indicates a leak has formed, and we can alert the wearer.”

The sensor communicates via Bluetooth connection with the user’s mobile phone through a custom app that processes several metrics. One feature of the product is that it can alert when the user’s heart rate is unstable, or if mask fit develops a leak.

“Your heart is pushing a lot of blood through the body, and the ballistic force is quite strong,” Hester explains. “We were able to sense that force as the blood travels up a major artery to the face.”


The device does not offer any explanation as to why the user would have a heightened heart rate. 

The announcement also didn’t touch upon major health issues that can occur with protracted mask or medical respirator usage, such as carbon dioxide saturation and oxygen deficiency of the blood, syndromes that can occur in as little as seconds after the user applies his mask. 

According to Hester, FaceBit offers an initial step toward practical on-face sensing and inference. Hester also enthusiastically lauded the apparatus for it being a “sustainable,” “convenient,” and “comfortable” monitoring instrument for frontline workers and others.

“I’m really excited to hand this off to the research community to see what they can do with it,” he added.

What the gadget further doesn’t serve to study is the degree to which masks can deliver on what they are purported to do by government and corporate mandates, namely, to diminish virus-containing aerosols—if at all—simply because the instrument was not built with a sensor capable of detecting pathogens, let alone measuring them.