In search of a personal respirator
Face masks protect against the spread of COVID-19 but are also worn to filter out harmful pollutants. The issue is that the exhaled breath can create sensations of heat, humidity, bad breath and discomfort, especially during prolonged exercise. An international team of researchers headed by Seung Hwan Ko wanted to make a respirator that could automatically adjust its filtration characteristics in response to changing conditions.
“The recent emergence of highly contgaious respiratory disease and the underlying issues of worldwide air pollution jointly heighten the importance of the personal respirator,” the researchers explain the motivation for their project.
Dynamic air filter
To address the issue, the researchers introduced adaptive respiratory protection based on a dynamic air filter driven by machine-learning algorithms. The filter has micropores that expand when stretched, allowing more air to pass through. They achieved a large increase in the breathability of the filter with only about a 6% loss in filtration efficiency. The filter is connected to a portable device containing a sensor, air pump and microcontroller chip. It communicates wirelessly with an external computer running AI software that reacts to particulate matter in the air, as well as changes in the wearer’s respiratory patterns during exercise.
It looks like any other face mask respirator except for two tubes that run down from a pair of rings at either side. As the conditions change, these tubes open or close the rings. The stretching or relaxing of this dynamic filtration fabric is what increases or decreases airflow. If you enter a polluted environment, airflow is sacrificed for filtration efficacy. And if you start exercising and breathing heavily, airflow is increased at the cost of filtration.
Interestingly, the AI software allows the respirator to adapt to individuals’ unique respiratory characteristics, which could be used to develop a personalized face mask. But the researchers are first focused on making the system smaller, lighter and less cumbersome. The goal is to redesign the stretcher to have a pump-free mechanism.
Now, think about all those rides through a polluted city in rush hour. Would you be interested in a personal respirator? And how about bicycle couriers?