UNLV students win prize for creating microwave for COVID disinfection

Scott Isler, 33, and Jeffrey Topacio, 32 — who both graduated in December — were recently named grand prize winners for UNLV’s fall semester Fred & Harriet Cox Senior Design Competition for engineering and computer science students.

When Isler and Topacio started working on their project over the summer, it was a capstone school assignment they needed to complete a degree. Their topic was a response to reported concerns over a potential shortage of ventilators for critically ill COVID-19 patients.

Over the months of work, “it opened our eyes to what we can do and what’s possible,” Topacio told the Review-Journal.

In their project materials, Isler and Topacio wrote: “Our project aims to greatly reduce, if not eliminate, the spread of viruses such as Covid-19 and bacteria through air circulation systems. It could also be fitted onto current hospital ventilator systems eliminating the need to continually replace air filters contaminated from patients with respiratory issues.”

High-efficiency particulate air filters for ventilators need to be changed, Isler said, and that’s done by technicians who dispose of them properly.

What differentiates their prototype device from others is there’s no physical filter, Topacio said. “There’s no replacing of anything, really.”

UNLV’s senior design competition was held virtually Dec. 16-17, and industry representatives served as project judges. Cash prizes were awarded to students in multiple categories, thanks to sponsors and the Cox family. Isler and Topacio were surprised to learn they’d won the grand prize — $500 each.

UNLV runs a senior design competition twice a year — for fall and spring semesters — and it has been up-and-running for 20 years.

About 30 teams and more than 100 students took part in the fall semester event in December. About $14,300 in prize money was awarded during the event.

“I want to really show off our students and what they are capable of,” said Rama Venkat, dean of the Howard R. Hughes College of Engineering, noting venture capitalists may take an interest and put money behind student projects for further development.

Overcoming obstacles

Because about 80 percent of UNLV’s classes were offered remotely during fall semester due to the COVID-19 pandemic, the two teammates build their prototype in Isler’s garage. They started the project in August.

It cost about $700 to make their prototype. Thanks to sponsors, UNLV provides financial assistance to student teams for costs associated with their design project.

Beyond the challenges of building a prototype, Isler and Topacio faced another major hurdle: not being able to access lab space to test their prototype to see whether it was effective in deactivating the COVID-19 virus.

Isler said they reached out to many people — including the governor’s office, university faculty and public health laboratories — but everyone was understandably bogged down by the COVID-19 response.

The alternative was finding someone actively infected with COVID-19 and asking them to blow into a tube, but that was a risky proposition.

Topacio said he was worried the lack of lab testing and data would invalidate their project, but understands why they weren’t able to access lab space.

Now, Isler and Topacio are continuing to work on their prototype as a side project, even though it’s no longer a requirement since they graduated in December. They’re also doing engineering internships, and Topacio will soon start a full-time job.

Topacio said the two are thinking about doing more redesigning and computer analysis for their prototype. They’re also waiting to hear back after contacting some judges who expressed interest in helping them connect with others to potentially help advance their project.

Building a prototype

Initially, Isler and Topacio were working on a different team project for the design competition, one also related to microwaves. “Then, the coronavirus outbreak happened and there was talk about a shortage of ventilators, potentially,” Isler said, noting they wanted to help.

All of their team members were on board and willing to pivot to something related to ventilators, so they reached out to their adviser, who allowed Isler and Topacio to leave their team and start a new project.

After getting a high-powered microwave, Isler and Topacio drew preliminary designs.

Topacio said they played around with different types of air pumps and water pumps. “It came down to a lot of trial and error.” And with a limited budget, “we tried to make the design as simple as it could be with it having some scientific basis.”

In their project materials, Isler and Topacio wrote: “A small feed of water will marry with air from a pump at a pipe tee where they will enter into the microwave cooking chamber. The flow will travel through a length of polytetrafluoroethylene (PTFE) tubing that is transparent to microwaves which will raise the temperature of the water-air mixture before it exits the microwave through the tubing outlet.”

With limited resources, the team exercised creativity while running tests. “We were literally taking temperatures with a kitchen meat thermometer at one point,” Topacio said.

Isler, who has two babies at home, said he went into the project knowing you can sterilize a baby bottle by submerging it in boiling water for five minutes. And with the engineering project, he said, the purpose was to ensure the COVID-19 virus could be killed in a very short amount of time.

One of the hurdles: There’s very little research on how high the temperatures needed to be to deactivate the COVID-19 virus.

French scientists posted a paper in April via preprint server bioRxiv — meaning it was shared publicly before being published in a peer-reviewed journal — that showed the COVID-19 virus was deactivated after 15 minutes of being exposed to temperatures of 92 degrees Celsius (or 197.6 degrees Fahrenheit) in laboratory tests.

The highest internal vapor temperature Isler and Topacio recorded with their prototype was 248.3 degrees Celsius (or 478.94 degrees Farenheit) with an air flow rate of 38 liters per minute, according to their written project materials.

Isler said it was important for them to disinfect using simply water because while there may be chemical products that work better, water is better for environmental considerations.

Contact Julie Wootton-Greener at jgreener@reviewjournal.com or 702-387-2921. Follow @julieswootton on Twitter.