New Device Could Increase Lifespan Of N95 Masks

Sep 30, 2020

A northern Illinois company is looking into ways to extend the life of N95 masks, especially in the medical domain. 

N95 masks have long been used by doctors, nurses and other health care workers for their ability to protect the wearer against airborne diseases. The masks can filter out 95% of incoming particles, as long as they are properly fitted and maintain a tight seal with the face. But the coronavirus pandemic has demand far outstripping supply, particularly when considering CDC recommendations.

“We needed that 3.5-5 billion. At the beginning of March, we only had 30 million in the national stockpile."

Bryan Nelson is a mechanical design engineer at F.N. Smith Corporation, a precision machining firm in Oregon, Illinois. The company has been looking at ways to extend how long people can use the masks before being thrown away. To do this, they take into account how these masks keep out disease. Three layers of material impede airborne particles. The second layer has an electrical charge, which pulls particles to it like a magnet. Nelson said this charge degrades over time or when doctors decontaminate the mask with agents such as UV light, steam or hydrogen peroxide.

“A lot of those methods reduce the electrostatic charge," he said, "so we tried to look at how could we increase that electrostatic charge to increase the effectiveness and the ability of the device to protect the end user, the frontline workers.”   

F.N. Smith’s solution is to “recharge” that layer in the mask.   

"So when we are able to charge it by slamming basically one side of the material with electrons, we can shift electron structure in the material, which causes that electrostatic buildup and allows us to pull things out of the air more efficiently," said Nelson.

The company is designing a device that would do just that. Nelson showed off an inner component, where the mask would be placed under a series of black rods pointing downward. At first glance, it looks like nails waiting to be lowered. But Nelson said there’s more at work.  

“We would hook up a power supply to this, and then those will, a certain charge of the power supply, and that will emit the electrons to the mask’s surface, which will cause that buildup in electrostatic charge.”

Nelson said this component would go into the final design.

“The end unit would be a bit smaller than a microwave and would use a standard wall outlet to work.” 

A handheld instrument could then be used to measure the mask’s new charge level. Nelson said the design draws upon previous research into electrostatic charge and materials, including from NASA. He said the results are promising.

“In some of this, especially with polypropylene (the filtration layer), they said it could be recharged up to ten times. Now that doesn’t mean you would have to recharge it after decontamination. Typically, from studies such as Stanford, there was a 3-4 times of decontamination, then you would see the drop in electrostatic charge.” 

F.N. Smith has a patent pending on its device and has reached out for certification from FEMA and the Department of Health and Human Services. But Nelson said the company doesn’t have the industrial capacity for mass production.

“We’re looking to reach out to industries that are underutilized in their manufacturing capability, such as aerospace or bar and restaurant equipment," he said. "Because we see that there’s a slowdown for them right now in manufacturing, and we’re hoping their ability to mass produce devices could supplement our technology.” 

The choice of partner would then shape the look and inner workings of the device.

“For the most part, we’re just waiting to have the final design of it based on the manufacturing capabilities of those manufacturers, what tooling they have so that we can work with them on it instead of having to create new tooling which could create a lapse in time before the device is out on the market,” Nelson said. 

Though the final design and production is still forthcoming, Nelson said a device like this could help alleviate the shortage of N95 masks. It could restore masks that lost their charge in storage as well as extend the life of those already in use. That could have ramifications for health care workers both during and after the pandemic.