Hospitals on Oʻahu have been stocking up on personal protective equipment (PPE) to help prepare for any future outbreaks of COVID-19. The University of Hawaiʻi at Mānoa School of Architecture has developed a method to produce face shields at an accelerated rate by using a computer numerical control (CNC) router to cut through multiple layers of clear polycarbonate sheets, which is used in conjunction with 3D printed components to create the face shield.
Steven Hill, director of the fabrication laboratory in the School of Architecture, wanted to help produce PPE and connected with Micah Ewing, director of technical architecture, from Hawaiʻi Pacific Health (HPH) who was coordinating an effort to produce 6,000 face shields from local makers.
The face shield design Ewing’s team created consisted of two 3D printed plastic pieces which snap together to form a headband. Even though the HPH design was very effective, it was not optimal for the School of Architecture’s 3D printers. Hill explains, “We use stereolithography printers here, which are great for detail, but are considerably slower than the filament-style printers many others use. We continue to print the headbands, but this is a group effort and other shops are much faster at that.”
Ewing and Hill brainstormed other ways UH Mānoa could contribute and discovered it was more productive to cut the actual clear face shields on a CNC router. HPH brought Hill a few boxes of clear polycarbonate, a very tough material, to experiment with. The polycarbonate provided much better visibility than other materials, and the .030 inch thickness made a very robust barrier that can be disinfected and reused several times.
“The polycarbonate shield material has proven to be the most valuable component,” said Ewing. “Polycarbonate is really scarce and it was crucial for us to get the highest yield out of the material we had—Steve worked with me to optimize the yield of shields from the material.”
“After trying to cut the polycarb with our lasers, we found we can stack the sheets and cut multiple layers at one time using the CNC router, so it is by far the most effective method for us,” said Hill. “Nicholas Hunsinger at the art department shop pitched in with the use of their CNC as well. It has turned out to be a good part for us to make here. In fact, it is so efficient that we quickly ran through all the material HPH supplied.”
Clinicians and first responders are finding they prefer the polycarbonate shields.
“The thicker polycarbonate shields cut by Steve and his team have been a big hit with caregivers throughout the organization as it gives superior optical clarity and less fogging, which is ideal for things like seeing the readings on IV pumps,” said Ewing.
Hill and his team of architecture students Keola Annino and Beau Nakamori are continuing to help supply face shields to hospitals that are running low on PPE.
Hill discovered that Kuakini Medical Center was in desperate need of 150 face shields, after its assigned shipment never arrived. He has recently acquired a new supply of polycarbonate sheets and offered to supply Kuakini with PPE.
“I am going to try and experiment with the recently released Apple design because we can do it exclusively on our CNC Router,” said Hill. “We feel fortunate to have a range of tools we can deploy until we find the best solution. Being able to help supply hospitals with face shields has been a way for my team and I to contribute to the community.”
—By Sarah Hendrix