M.A.P.

When my country declared an emergency, I had a bad feeling that I couldn’t put my finger on. I couldn’t really wrap my head around it at that time – I was in a fog. It was January 23rd, 2020.

The next day, my mother came to Shanghai from Hungary to celebrate the Spring Festival with me. When I picked up her at the Pudong Airport, she had a face mask on. The next day, we heard that there was a quarantine imposed by the government. My mother was a biology teacher in Macao so she realized that the situation could become serious very quickly because Macao has the highest population density in the world. She also knew that it would be very difficult to determine who carried the virus unless they were diagnosed. Wearing a mask was not only to protect ourselves but also for the safety of others. So she went back to Macao two days later to get about 70 masks for me. She bought them in Hungary, but they were marked ‘Made in China.’ Thanks to my mother, I was able to obey the laws in China and go outdoors during the quarantine with a mask on. Later, I was able to use these masks for testing.

As people were staying home for much longer periods than before, they were learning a lot about the virus from TV and the internet. It slowly dawned on me what the bad feeling I had earlier was all about: even though there were more people in China infected than anywhere else, it would soon become a worldwide pandemic. China is the biggest face mask manufacturer in the world, and most of them are made in Xiantao, a city right next to Wuhan. The world’s mask supply was coming from ground zero of the epidemic.

People started asking, ‘How hard could it be to make mask?’ We soon found out: a machine can sew a mask in half a second, but it takes a week or sometimes up to to half a month for them to be ready for use. The masks need to be sterilized by epoxy ethane gas and then the mask needs to be naturally aired out before packaging for shipment. While waiting for the masks to be made, people were on their own. It became clear that in the very best scenario, it would be Valentine’s Day before any new masks were available.

I calculated how many masks the Chinese people would need. Later, I needed to refactor as it became a global pandemic. I was shocked. By my calculations, we needed to produce over 500 million masks a day! I think this was a major reason for the government wanted to warm people that they needed to stay home. I’m pleased to note that most people in China did stay home.

But we need to go outside to survive. We need to go outside to buy food, and when we go outside, we need to wear a mask. But if masks are in short supply, what can we do? Some people tried to boil disposal masks, or spray alcohol on them to disinfect them. Medical professionals warned us that this can ruin a mask. This is fine for an ordinary cloth mask, but it doesn’t work for N95 or PM2.5 masks. An N95 mask blocks the virus not only because of the density of its filter but it also needs to be statically charged to capture particles. Not many people knew this before this pandemic. Using alcohol dissolves the middle layer, and hot water removes the static electricity needed to make the mask useful. The only acceptable way to sanitize a mask is to apply a UVC light or hot, dry air. This way it doesn’t damage the mask as much because it doesn’t remove the static charge while the masks are being disinfected. The electricity will still dissipate after a day or two, but it’s still better protection than not sanitizing at all.

So could we find a way to recharge a mask? If we could get them disinfected and recharged, they could be at least 90% renewed. The more people that did this, the less of a shortage and panic we could have during the first stages of a pandemic.

I started to research the possibility of making a tiny factory at home and I had an insight. An ordinary factory uses epoxy ethane after the mask is sewn because it is more efficient given the number of masks they produce. They cannot sterilize the cloth before they sew it because the machines would pollute the mask. However, for home use, production volume would not be a factor. Perhaps we can completely sanitize a used mask without worrying about removing the static electricity and then recharge it later.

I checked the price of high-voltage static electricity charging machines and was disappointed. The only ones I could find were for industrial use. Besides being too large, the price of the available units were getting more and more expensive because factories needed them to produce more masks. I’m was sure there was another solution besides bringing a full-scale mask into the home or into a community center. I needed to make it portable, or at least desktop-sized, and I needed to make it affordable so people could turn their places into tiny factories and come to rescue in the early stages of a pandemic.

So I got an international team together to help me. I, Kalimov Lok, am doing the principle experiments and making the prototype. Jason Liang, PVCBOT maker, is trapped in Yichang, Hubei, near Wuhan, so he is doing market research and experimentation. Torrey Nommesen is an American currently quarantined in South Africa, and is making our web site and helping with English language press for our project. Daniel Feng, an industrial designer in Guangzhou, will work on finalizing the design for production once the prototype is built. John Lee, a professor in Zhongshan, is helping us with production and manufacturing. We have been working since March. We will post our progress online at http://maskaidproject.com/ if you are interested in following our journey.

Since the scale of this problem is so large and we hope that many hackers and makers will work with us, M.A.P. will be an open-source project. We will soon be looking to crowd-fund and share our knowledge as we develop it further.

Pictures below:

This is a drawing of an early design idea. We knew that non-woven masks can be boiled in hot water, so we planned to use hot water to disinfect them. I designed a frame that can fit a dozen face mask in it with a handle so that it can be turned 90 degrees while boiling in hot water. Then you can put the unit under a UVC light and use hot air to dry.

Later, I revised my idea. This is a triple-layered box. Hot water is pumped through the middle layer to immerse the face masks. After the hot water treatment, a valve is opened and the water flows back into a tank. Then hot air blows to dry the masks. Lastly, we put all masks to a top layer and use a spark room to static charge the masks.

This is a design I created before coming up with the M.A.P. Project. As single-use face masks are in short supply, why not use something washable that cannot be infected? Alcohol kills bacteria, so I came up with the concept to filter the air with alcohol. A USB air-pump pumps air into a tank half-filled with alcohol. A cloth covers the alcohol to reduce that amount that gets vaporized. We cannot breathe alcohol vapor so I added another tank half-filled with glycerin. A plastic mask is connected to the second tank to breathe the filtered air from. I also designed a unit that you can wear on your back like the units used in combat situations.

In mid of March, while I was walking pass by a convenience store, I saw a sausage roasting machine blinking at me and I got an idea. Our team was debating whether a desktop or portable machine would be better. Both have pros and cons. We argued about its efficiency vs size. But if a mask is wrapped around a pole, we could minimize space. If you wanted to process a large number of masks, you could group them together in a bundle that looks like a WWII German grenade. An image that conjures up a war against the disease! I grabbed a 50mm thick PVC pipe and tried putting a mask in it. I worked!

I found a cheap, tiny, high-voltage generator to try and statically charge a mask. It burnt a hole in the mask.

For the second test, I tried using an array of pins to avoid sparking. This failed too. It left a series of holes on the mask. The good news was that the holes were smaller than in the first experiment.

For my third experiment, I used smooth aluminum foil as the positive pole and the same foil on the board as the negative. A smooth surface can make an electric field stay still while polarizing the non-woven middle layer. It was silent for a while, but then a much bigger thunder crack sounded. This created one big hole on the top-left. Compared with the previous tests though, the middle part survived better. But it turns out that even in the highest quality product, we are not able to create a smooth enough surface to avoid damage.

I noticed that if the poles were thin and close enough together, like those found in a brush, the spark would become small enough that it would disappear and not harm to mask. We needed a very soft and highly conductive material. I tried to find a carbon fiber brush from Taobao, but I couldn’t find anything suitable. To get the size brush big enough for our purposes, it would be too expensive. I think the reason for the higher prices was because these parts are needed in the commercial mask manufacturing process, so they were in high demand. Many sellers had brushes that were 20 cm long, specifically for mask making. So I thought that maybe I could use thinner poles instead.

I tried to think of other materials that could be used that would not be needed in commercial mask production. Carbon fiber was still a good choice, but if I searched other keywords not related to face masks, I might be able to find an affordable material to use. I found three potential candidates: graphite felt, carbon-fiber non-woven cloth, and carbon-fiber cloth for model decoration. I bought some samples from Taobao.

This is graphite felt. It is used in industrial manufacturing to prevent leakage of dangerous static electricity and ground it. It was too big so I used a structure to hold it. The green piece in this picture was a failed 3D print leftover from the alcohol filter project. Although it worked better, the experiment was still not very successful. There were several holes burned into the mask at random points. Graphite felt was still too rough of a material.

For the next test, I used carbon fiber cloth. It was labeled 3K, which means about 3000 pieces of fibers per square inch. I neglected to record video or take pictures, but it produced both better and worse effects than graphite felt. If it was switched on for too long, there would be plasma flames and no sparks.

Stacking multiple masks at a time would be one way to solve this problem. But the distance of two poles had to be close in a portable version and the closer the poles, the easier the sparks or flames are made.

Jason Liang, our team member trapped in Wuhan, ordered a static electronic test meter for me via Taobao. Though half a dozen face masks were burnt with holes, I could still check how much static electricity stayed on the mask. The proper procedure for using the meter is to measure 10 cm away from the surface, but even a brand new mask couldn’t be measured this way as the electrons need to be captured in the middle layer. So I had to put the probe directly on the samples. The result proved that the Marx Generator was sufficient enough to charge masks. A newly opened mask has 4~5KV of static charge when new, and after 8 hours using it drops down to 1~1.5KV. I don’t have pictures but I tested by exposing a new mask to the open air in my office overnight and measuring the drop in static charge.

Next, I tested carbon fiber non-woven cloth, which was designed for wrapping computer chips. If I lowered the input voltage and I changed cloth, sparks would disappear and the noise was like small mosquitoes. This showed that the device could work with a safer, low voltage charge. One quality of the carbon fiber non-woven cloth was that the material was the thinnest of the 3, but it was also too big so I had to cut it to 5% of the original size. This meant that the price was less than 1/3 of others!

Face masks need to be hot dried in 50 to 70 degrees Celsius air. I bought several USB mouse pad warmers only to find that they would not get hot enough. At less than 40 degrees Celsius, my skin was warmer than the temperature that they could heat to. I cut one of the warmers apart and found that the heater was made of carbon fiber. This meant that it heating too smoothly got cold too quickly.

I didn’t have a saw big enough to cut the 50mm PVC pipe I purchased, so I 3D printed a shape to test the carbon fiber non-woven cloth. The circle in the center was used to hold a piece of 20mm PVC pipe standing up. Another pole would be attached to it.

Finally, resistance wire heating tested successfully. I plan on applying 3 ohms to the heating unit, and that should be suitable for our design.