Originally published: August 2020

Right now we are all looking at a pandemic that has completely turned our lives upside down. While the COVID-19 pandemic has made us much more aware of our shortcomings as a society, what is even more astonishing is that despite our advancements in science, we have not handled the situation as nicely as we would have liked. There is a big debate surrounding the fact that whether wearing face masks is as essential as everybody is making it out to be. On the other hand, health professionals themselves do not have the personal protective equipment (PPE) in place to protect themselves from the virus which puts them in harm’s way while doing their job.

Global masks shortage

Countries all over the globe found themselves scrambling for the PPE due to the shortage of it and excess demand at the time. But what really shone above all else is the N95 filter masks. Now what is this, and why is everybody harping on it?

The name N95 comes from the fact that the mask can prevent up to 95% of microbial particles from passing to our nose and mouth, especially viruses which are much smaller than other microbes. This gives the wearer a great deal of assurance that they’re protected while doing their jobs. It has been around since the year 1995 which was when the filters were created. It was created by a Taiwanese-American scientist, Peter Tsai.

So, who is Peter Tsai?

Peter Tsai was a research faculty at the Department of Material Science and Engineering at the University of Tenessee, Knoxville. He is the brain behind the creation of this fabric responsible for the filtration of the infectious particles which were created using a method known as corona electrostatic discharge method (Ironic now, isn’t it?).

Corona electrostatic discharge

The basic filtration mechanism can be of 4 types according to the experts at CDC and they are inertial impaction, interference, diffusion, and electrostatic discharge. The first 3 mechanisms can be achieved with ordinary face masks that are either made of women fabric or plain cloth and can offer better protection in the case of surgical masks.

But what makes N95 so different is that it is made out of fibers that have been created using the electrospinning method. In electrospinning, the fabric is made by pumping a polymer out of a syringe at very high pressure in a charged field which results in the creation of extremely thin nanofibers that not only have good tensile strength but are also charged in nature. This charged filter when placed inside a mask, can provide protection by attracting any particle in the air stream around us that is oppositely charged which in turn offers a much greater amount of protection compared to other masks. This is one of the reasons why it is so preferred in highly infectious environments and must not be washed because that could disrupt the charged mechanism that it possesses.

How do you sterilize the masks?

The filter earned the scientist a US patent in the year 1995 and what was even more incredible is that he came out of his retirement this year to figure out the best way to sterilize the masks so that they can be reused! This in turn solves the problem of the shortage in a way, for people who already have them so here’s the protocol in case you were wondering:

They must be hung in a dry air oven and heated up to 160o Celsius for around 30 minutes. To make this a more efficient process, the healthcare workers could buy 5-7 of these and rotate them while the others are being sterilized.

Previous studies have already validated the efficiency of the mask in preventing the users from getting infected and preventing transmission in itself. And no, the mask most definitely does not prevent oxygen molecules from getting through (to all the naysayers out there!) because these molecules are much much smaller than viral particles.

Final Word

This invention is proof of how medical ingenuity can directly impact the lives of people and save them in a time of unexpected crisis as well! This post is a virtual salutation to the team that designed this mask under the leadership of Mr. Tsai for their lifesaving invention.


The man behind the mask. (2020, April 17). Retrieved from

Andrew, S. (2020, July 16). He invented the N95 mask filter. Then the coronavirus pandemic hit and he was called to help once again. Retrieved from

Wang, X., Pan, Z., & Cheng, Z. (2020). Association between 2019-nCoV transmission and N95 respirator use. MedRxiv.

Molina, A., Vyas, P., Khlystov, N., Kumar, S., Kothari, A., Deriso, D., … & Prakash, M. (2020). Project 1000 x 1000: Centrifugal melt spinning for distributed manufacturing of N95 filtering facepiece respirators. arXiv preprint arXiv:2004.13494.

You can check out my post on Coronaviruses on this link! 

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