A 3D printed mask is 8 times more effective than the N95

Rihal Digital Designs founder Dr. Amarjit Rihal was quarantined during the early months of the COVID-19 outbreak in Canada. Under new guidance from Health Canada, his dental lab was expected to close early because a lack of resources left his team with fewer than 10 N95 masks left.

Read on to find out how Rihal turned her anxiety into action and created a custom medical mask that’s eight times more effective than an N95 mask using free software and a Formlabs 3D printer.

A personalized medical solution

With masks quickly running out, Rihal wanted to create a customized medical solution that would keep his employees safe and cover his lack of resources. Equally important was to create a mask that was feasible and affordable so that it could be purchased by other practices and medical professionals.

What Rihal tried to do is a personalized medical device adaptation. Equipped with only a free 3D scanning app (Bellus 3D, an app used for other COVID-19 projects), a free subscription to Fusion 360, and an SLA Form 2 3D printer, he set out to create a custom medical device.

In just one day, Rihal printed his first prototype on the flexible resin Form 2. Homemade additive manufacturing allowed Rihal to quickly test his design and switch to Tough Resin, creating a better seal around the user’s mouth. This type of pricing efficiency for medical devices has never been achieved in the medical field, and innovators like Rihal are demonstrating how a combination of low-cost technologies can reduce costs and development time to improve outcomes for frontline workers.

The accuracy of the engineering materials was key to the delivery of his mask, and Rihal noted how «the overall quality of the resins is excellent. Prototyping in hard resin allowed me to connect and play with the P100 filter because the parts were so precise. Plus, I could easily sterilize the components, which was great.» Using a standard P100 filter means this mask model can easily be shared with others as a standalone mask model without having to ship or order specialized filters.

Once the P100 filter was applied, only one problem remained: the mask overheated when worn.

In the Fusion 360, Rihal has modified its design to add better ventilation. Within a few hours, the part was printed and ready for testing. The improved, definitive design can be worn comfortably all day whilst providing high levels of protection.

Even Rihal was slightly surprised by how the new mask performed under rigorous testing. According to Rihal, «Face masks can be tested in a closed room where particles are released into the air to visualize airflow. Users must breathe, speak and move their head. Under these conditions, a standard N95 mask has a fit factor of 200. My custom mask generated a score of 1,600, eight times better than the N95.»

Rihal is now going through the process of making his mask widely available and approved by Health Canada. He believes BioMed’s clear resin may be the best resin to use for his application because it has all the properties he needs to get mask approval, but regulatory approval.

Early investment in additive manufacturing

Rihal then created Rihal Digital Designs, a fully digital dental CAD/CAM services laboratory and design center to produce dental prosthetic solutions for patients while maintaining digital workflows. Created an efficient digital workflow, orally scanning patients and 3D printing orthodontic models for clear alignment/split therapy.

Rihal’s first in-house SLA printer was the Form 1+, which is still printing custom trays five years after purchase. Having used Formlabs SLA printers for many years, Rihal felt comfortable editing, creating and printing digital files for this custom mask. “I felt very comfortable knowing my limitations and those of the printers. In digital dentistry I am always dealing with STL files, so they were nothing new, and I have been using PreForm for many years to send prints to the Formlabs printer,” said Rihal.

Additive manufacturing for medical services

Formlabs has been working in the fight against COVID-19 since March 2020, determined to help the medical community use 3D printing to address the pandemic and associated supply chain shortages. Formlabs has collaborated with dozens of healthcare providers and government agencies around the world on various projects involving COVID-19 testing, PPE, and medical equipment.

For example this page you can find information about applications currently available for medical professionals and for non-clinical use. You’ll also find stories highlighting how Formlabs users overcame local challenges and shortages to help fight the pandemic.