MIT (Massachusetts Institute of Technology) has long been associated with training leading scientists and technologists. Now, the university has jumped into the fray to meet critical medical supply shortages, as a MIT team earlier this week launched a new mass manufacturing technique to meet the high demand for disposable face shields.
According to an article on the university’s website, the single-piece face shield design will be with a process known as die cutting. Machines will cut the design from thousands of flat sheets per hour. Once boxes of these flat sheets arrive at hospitals, health care professionals can quickly fold them into 3-D face shields before adjusting for their faces.
“These face shields have to be made rapidly and at low cost, because they need to be disposable,” said Martin Culpepper, professor of mechanical engineering, director of Project Manus, and a member of MIT’s governance team on manufacturing opportunities for COVID-19, in the article. “Our technique combines low-cost materials with a high-rate manufacturing that has the potential of meeting the need for face shields nationwide.”
Culpepper and his team at Project Manus spearheaded the development of the technique, collaborating with partners from MIT, local-area hospitals and industry. The team has worked closely with the MIT Medical Outreach team and the Crisis Management Unit established by Vice President for Research Maria Zuber and directed by Elazer R. Edelman, the Edward J. Poitras Professor in Medical Engineering and Science at MIT.
While face masks are commonly used by health care professionals, there’s concern that due to shortages, masks often have to be reused, heightening concerns about spreading virus particles.
Face shields add a protection layer that covers masks and entire faces while extending the life of personal protective equipment. The shields are made of clear materials and have a shape similar to a welder's mask. They protect the health care professional and their face mask from coming in direct contact with virus particles spread through coughing or sneezing.
Culpepper and his team at Project Manus set out to design a face shield that could be rapidly produced at a scale large enough to meet the growing demand. They landed on a flat design that people could quickly fold into a 3-D structure when the shield was ready for use. Their design also includes extra protection with flaps that fold under the neck and over the forehead.
Culpepper started prototyping the shield using a laser cutter he had in his house. With some design input from his children, he tested different materials and made the first ten prototypes at home.
After testing a few materials that cracked and broke when bent, the team chose polycarbonate and polyethylene terephthalate glycol—known more commonly as PETG—as the shield’s material.
In addition to making more prototypes at the Project Manus Metropolis Makerspace using a laser cutter, Culpepper worked with Professor Neil Gershenfeld and his team at MIT’s Center for Bits and Atoms (CBA) on rapid-prototyping designs for testing using a Zund large-format cutter.
After building several prototypes, Culpepper and his team tested the shields with advice and practical feedback from Edelman, who is also a physician. Participants found that in addition to being easy to assemble and use, the MIT-designed shields provided good protection against coming in contact with virus particles through splashes or aerosolized particles.
Before moving into manufacturing, Culpepper’s team tweaked the face shield’s design to maximize coverage around the neck and sides of the face.
The die cutter machines used in mass manufacturing will produce the flat face shields at a rate of 50,000 shields per day in a few weeks. The manufacturer will continue to ramp up manufacturing further, with the ability to fabricate in more than 80 facilities nationwide.
MIT plans on purchasing the first 40,000 face shields to donate to local Boston-area hospitals this week and the fabrication facilities will donate 60,000.