William Liu, a Laidlaw Scholar from Tufts University, works with a bicoastal engineering team to enhance PPE for medical professionals using snorkeling masks and 3D printing.

Excerpt from TuftsNow article by Laura Ferguson, published on April 16, 2020. Read full article here.
Photos: Courtesy of William Liu

Jan Sliwa, A06, M11, an anesthesiologist at Scripps Mercy Hospital in San Diego, had an idea to help protect emergency and operating room doctors from the COVID-19 virus. It started with snorkeling masks.

By design, the masks offer full-face protection. But there was just one hitch. He needed adapters to connect the snorkel side of the mask to antiviral filters widely used in hospitals. That single device, he thought, would eliminate the worry of coming in contact with contaminated air droplets or vapor.

Innovation, as it so often happens, thrives on collaboration, and in this case, it was bicoastal and fast-acting. The manufacturing of the prototype Sliwa envisioned—as designed by Stanford engineers—happened at a Tufts makerspace thanks to the quick response of William Liu, a junior majoring in mechanical engineering.

Liu had been active at the Nolop Fabrication, Analysis, Simulation, and Testing facility—Nolop for short—and was eager for the challenge. “Engineers are about being engaged and being focused on problem solving,” said Liu. “I wanted to do what I could to help.”

“It was great to see William spring into action,” said Barrett Larson, physician founder and director of the Stanford Anesthesia Innovation Lab, where the adapter was designed. “He worked well with engineers at Stanford to make sure the new prototype was printed to exacting specifications, and delivered the first order to California in a matter of days.”


The project traveled across country to Tufts thanks to family ties—Sliwa’s father is Krzysztof Sliwa, professor physics and astronomy at Tufts. Krzysztof Sliwa then contacted the Tufts School of Engineering and their 3D printing lab, and soon reached James Intriligator, professor of the practice in mechanical engineering and Human Factors program director. Intriligator reached out to Liu, who was an undergraduate researcher in the human factors lab, and told him about the project.

Liu received the design file for the adapter on March 29, and was drawn immediately to the challenge of figuring how the adapters could be printed on six Prusa 3D printers.

Before he went into full mass production, Liu completed a test round with ten adapters.

They came out well, so he put the printers to work overnight, manufacturing a total of 120. Not all met exacting specifications, but eighty devices measured up. He hustled them over to a Somerville UPS store and they arrived the next morning at Scripps Mercy Hospital and Stanford.

“What Barrett and William accomplished was a one-piece design that eliminated the need for any gaskets or other points of failure—3D printed from a material that didn’t require any post-processing, thereby eliminating any leaks that might let virus sneak in,” said Sliwa. “They were able to do that in under a week—and well in advance of our expected surges in San Diego and Palo Alto.””

3D printing of adapters

“After hearing the good news from the Scripps Mercy Hospital, Liu sent twenty-one more adapters to three different locations in California. “Barrett told me that they look very promising,” he said, “and I will keep making more to prepare for future supply.”


Brandon Stafford, director of the Nolop makerspace at Tufts, said he was not surprised by the alacrity with which Liu approached the printing challenge; he has the kind of creative mind that Nolop, which opened in 2019 as a community makerspace, seeks to encourage. “He and his roommate, Eric Wu, are forces of nature” as engineers, he said. “They just want to build stuff all the time. Nolop is a very satisfying place for them.”

Indeed, Liu has an abiding passion for what he calls visual thinking. Growing up in Shenzhen, China, that skill was honed as he competed with a top-performing robotics team throughout in middle and high school; for six years in a row that same team was chosen to represent China in the Robocup Junior International Competition.

As Tufts he’s continued to excel as a student leader. He is president of the Engineering Student Council and last year he was selected as one of twenty-five Laidlaw Scholars, giving him the opportunity to work across multiple disciplines under the supervision of Intriligator in the Human Factors Research Lab, a catalyst for a wide range of devices for physical and digital prototyping.

With family in China, Liu was concerned about the spread COVID-19 before most of his classmates; his parents were quarantined for two months earlier in the year. Now, as the disease claims thousands of lives across the United States, and as social distancing restricts his own movements, he said he is just trying to his “small part” to bring hope to others. “I wasn’t able to do anything to help my own family,” he said. “So it’s good that now I try to do something here.”

Liu’s expertise with 3D printing has also made him the go-to person yet another medical device, a surgical mask strap for health-care providers at Tufts Medical Center. The Ear Savers, whose plans are available online, hold the elastic straps of a surgical mask, relieving pressure on ears. “Nurses loved it! I’m on my way to Nolop now to mass produce 500 more,” Liu reported on April 13.  

And by being immersed in the inventive, pragmatic opportunities offered by engineering, Liu has an even clearer picture of what he wants to do next. The unexpected bicoastal partnership came at the time he was finishing up his application for graduate school.

Tufts,” he said, “is the only school I’m applying to. That’s how much I love it.””

Read the full version by Laura Ferguson on TuftsNow