After many futile trips to grocery stores and home improvement stores in search for face masks, I had to accept the reality that there is no high-quality face mask to wear to work even though I know someone in my building who has already been diagnosed with COVID-19. Eager to find alternatives to face masks, I learned that respirators, with the proper filters, could provide similar levels of protection against airborne particulates. Just a week after I started building my 3D respirator model, I received an email from a current physician at University of Pennsylvania (UPenn) who is desperately searching for PPE so she can protect herself and her colleagues while treating patients who have chronic diseases and may also have been exposed to COVID-19. From that moment, I realized that the safety and efficacy of my 3D respirator design is not only responsible for my well-being but also the well-being of many physicians and their patients. My user group has just changed from a doctor, a worker, or a patient, to people whom I personally know.
Personal protective equipment (PPE), including respirator masks, are being redirected from other uses to Emergency Response (ER) doctors and medical workers in direct contact with COVID-19. Even with redirected resources, there is still a shortage of available PPE at many hospitals and critical sites. Other essential workers (delivery workers, grocery cashiers, restaurant chefs, research lab assistants, etc), who are unable to social distance are at risk of getting infected with COVID-19 but have a hard time obtaining protective gear due to focus on the frontline workers.
Due to the shortage of respirator masks, it is critical to maximize usage from each available mask. However, many of the respirator masks in use (such as surgical and N95) cannot be effectively reused, as any type of stringent disinfectant strong enough to kill microbes would cause the mask material to lose its effectiveness against the virus and reusing a contaminated mask defeats the purpose. Face shields being mass-produced around the country, although reusable and effective against droplets, do not offer any protection against breathing in the airborne virus.
What it does
This respirator design can accommodate your material of choice as the filter. Each conventional surgical mask, such as surgical / N95 masks, can be cut into four filter "discs", effectively increasing each mask's lifespan by four times. The inlet of the filter shroud diverts airflow by 45 degrees, further lowering the chance of dangerous particulates entering or leaving the mask. Upon many printing iterations with different filament materials, the Verbatim PRIMALLOY material was selected which is flexible and comfortable when pressed against one’s skin. The external surface of the filter can be disinfected by directly spraying 70% ethanol/isopropanol alcohol without damaging the hydrophobic property of the mask. We worked with physicians at UPenn to understand their concerns and optimize our design. Three different sizes have been created for our respirator. Moreover, the surface structure of the respirator was rigorously modeled to facilitate ease of disinfecting. The size and shape of the filter unit have also been optimized to reach a balance between breathability and level of protection against aerosol exposure.
Combined ## How we built it, ##Challenges we ran into, and ##What we learned The Tinkercad software was used to build the entire design and the PRUSA I3 mk3 printer was utilized to produce the ultimate product. It was an iterative process of designing the mask and then printing it to test for usability. During the process, I faced many challenges: (i) even though the face-piece was designed to fit a person’s facial structure, the face-piece either left a thin gap when pressed against my face or was so tight that it bruised my face. A tight seal is crucial because any small gaps between the face and the respirator could drastically increase the risk of disease particulates leaking into the respirator. After many trials with different filament materials, I was able to find the Verbatim PRIMALLOY filament which is flexible enough to fit tightly to my face and soft enough to be worn for a long period of time; (ii) knowing that surgical masks are in dire shortage, I began searching for alternative filter materials and incorporating the flexibility to accommodate different levels of material thickness into my design. After trying many materials such as cotton pads, HEPA (high-efficiency particulate air) filter, cloth, and sterilization wrap, I determined that the HEPA filter could be adopted as an effective filter for our respirator as it blocks out particulates and is breathable at the same time; and (iii) I learned the hard way that a respirator design with well-thought features alone is not enough. Many of the previous versions of my model failed to print or took an unrealistic amount of time to produce. To boost scalability and ease-of-produce by other makers in the community, I optimized my design through many iterations so that it is easier and faster for even a low-end printer to produce a respirator.
Accomplishments that we're proud of
Based on feedback from medical professionals, this design resolves many of the weaknesses in other similar 3D respirator mask designs. After encountering failures in 3D printing and overcoming the aforementioned challenges, the 3D design was improved and is currently in use by some physicians at UPenn, helping to reduce their risk of contracting COVID-19. At a time when people observe social distancing and many stores are shut, our 3D design was developed with scalability and speed in mind. It can be readily shared with the maker’s community and printed at home in a short amount of time.
What's next for Masks for Hope
With funding, our next steps would be to purchase more 3D printers and materials to increase the production of our respirators. Moreover, we will continue to improve our model based on feedback from medical experts and promote our design to help more communities in shortage of PPE.
Currently, there are 3 different adult sizes for the mask. With more time and resources, we can alter the respirator design to accommodate smaller faces, such as children, who are also vulnerable to COVID-19. Due to variations in children’s face sizes, additional considerations will need to be made to ensure that there is enough breathing area without compromising the tight and comfortable fit to the face. Moreover, if given more time, we could further customize the mask with different colors, appearance and even engrave text or name on the mask so the user can be more easily recognized and this mask would be more appealing to younger users.
We also plan to explore the possibility of mass producing our design by utilizing the current model as a mold and injecting materials such as silicone to more quickly produce an effective respirator mask. To further expand the impact of our design, we will seek collaboration with 3D printing companies with the goal to donate 3D printers preloaded with our design to communities that are in dire need of respirator masks. The efficacy of this design has not yet been tested by the FDA (Food and Drug Administration). However, due to the current urgency of the situation and lack of available protective masks, we have distributed this respirator to doctors who requested them. We made the respirator mask design available online with that caveat, with the intention that 3D print makers around the world can immediately contribute to the collective effort of including mask supply. With more user feedback adjustments and a funding sponsor, this respirator design can be submitted for FDA-approval.
Try It out
3dprinter, prusa, tinkercad-(3d-printing-software)