Engineers from Harvard and MIT University have developed a face mask that can detect Covid-19 infections and diagnose the wearer within approximately 90 minutes.
The masks are embedded with tiny, disposable sensors that can be fitted into other face masks, as well as clothing.
The sensors are based on freeze dried cellular machinery that was previously developed for use in diagnostic tests for viruses such as Zika and Ebola. The sensors may also potentially be adapted to detect other viruses.
In addition, the sensors can be used by healthcare workers by attaching it to their lab coats, offering a new way for them to monitor their exposure to pathogens or other threats.
“We’ve demonstrated that we can freeze-dry a broad range of synthetic biology sensors to detect viral or bacterial nucleic acids, as well as toxic chemicals, including nerve toxins. We envision that this platform could enable next-generation wearable biosensors for first responders, health care personnel, and military personnel,” says James Collins, the Termeer Professor of Medical Engineering and Science in MIT’s Institute for Medical Engineering and Science (IMES) and Department of Biological Engineering and the senior author of the study.
The face mask sensors are designed to be activated by the wearer when they’re ready to perform the test, and the results are only displayed on the inside of the mask, for user privacy.
The new wearable sensors and diagnostic face mask are based on technology that Collins began developing several years ago.
In 2014, he showed that proteins and nucleic acids needed to create synthetic gene networks that react to specific target molecules could be embedded into paper, and he used this discovery to create paper diagnostics for the Ebola and Zika viruses.
In 2017, he then developed another sensor system, which allows highly sensitive detection of nucleic acids.
These cell-free components are freeze-dried and remain stable for many months, until they are rehydrated. When activated by water, they can interact with their target molecules, and produce a signal such as a change in colour.
Collins and his colleagues then began working on incorporating these sensors into textiles for use in lab coats and fabric masks. First, they performed a screen of hundreds of different types of fabric, from cotton and polyester to wool and silk, to find out which might be compatible with this kind of sensor.
“We ended up identifying a couple that are very widely used in the fashion industry for making garments. The one that was the best was a combination of polyester and other synthetic fibers.”
To demonstrate the technology, the researchers created a jacket embedded with about 30 of these sensors.
They showed that a small splash of liquid containing viral particles, mimicking exposure to an infected patient, can hydrate the freeze-dried cell components and activate the sensor.
In addition, the sensors can also be designed to produce different types of signals, such as a colour change that can be seen with the naked eye, or a fluorescent or luminescent signal, which can be read with a handheld spectrometer.
The researchers also designed a wearable spectrometer intended to be integrated into the fabric, where it can read the results and wirelessly transmit them to a mobile device.
“This gives you an information feedback cycle that can monitor your environmental exposure and alert you and others about the exposure and where it happened,” Nguyen says.