5 guys create device to grill rib-eyes at right temperature

Five Rice University seniors are trying to make sure grill masters never undercook or overcook their steaks again.

The team, Five Guys & Ribeyes, has designed and constructed a functional prototype seven-sensor meat thermometer for the students’ senior engineering design project.

The idea for the new product came from one of the team’s faculty co-advisers, Gary Woods; as a grilling enthusiast, Woods has had the idea for the thermometer for about 10 years. He challenged the students to create a digital thermometer with multiple, closely placed sensors.

The Five Guys team is made up of four mechanical engineering students — David Cooper, Michael Fleming, Will Firth and Harry Sagel — and one electrical engineering student, Rico Marquez.

“We are using a food-safe multimaterial sheath primarily made of plastic, but with horizontally placed gold-plated copper casings every quarter inch,” Marquez said. “Inside each of these casings, we have placed a small thermistor to measure the temperature. The thermistors are wired to a printed circuit board and Arduino microcontroller, which displays the multiple temperatures on an LCD screen.

“When inserted into the meat, the array of sensors will provide a temperature profile throughout the depth of the steak. This will enable error-free grilling,” he said.

By using a multimaterial sheath instead of solely stainless steel, the team eliminated any unwanted vertical heat flow along the length of the probe but still allowed for fast heat conduction between the meat and sensor. The probe was 3-D printed using PEEK plastic and holds thermistors enclosed in copper casings along the length of the probe; the thermistors then provide fast, accurate and discrete temperature readings.

Current meat thermometers have only one sensor, and it’s difficult to know where that sensor is within the probe, Marquez said. That also makes it difficult to know where in the steak the sensor is taking the temperature reading.

So far the team said the thermometer is working great, and they’ve received a lot of positive feedback at the demos they’ve given, including presentations at Rice’s annual George R. Brown Engineering Design Showcase, which was held in April.

“A lot of people have been interested in the project,” Marquez said. “People would like to see us move forward with this and make it a consumer product that they can pick up at a local grilling store, and we really would like to do that.

“Since this was the first year of this project, it’s also possible more team members could be added here at Rice in the future to carry it on,” he said.

To that, Five Guys’ other faculty co-adviser, Gene Frantz, said one part of his involvement included asking questions of reality.

“I asked them, ‘What is this going to cost in volume production?'” Frantz said. “In my role, I could explain the different rules of thumb of how you determine what it is going to cost and what it should cost based on market and distribution to high volume.”

Both Frantz and Woods think this could be a project-to-market product.

Woods, who has been teaching capstone projects at Rice for seven years, is impressed with what the team has done.

“These guys have exceeded my expectations,” he said. “Rice students are really smart, and they’re very creative. They came up with ideas that I had never thought of for making this a more viable project. They took it and ran with it.”

“The whole idea of a senior project like this is so vital to preparing for the real world,” Frantz said. “There were several times they would come to a meeting and say, ‘Oh, I didn’t know this,’ and I’d tell them that’s a great lesson to learn.”

About David Ruth

David Ruth is director of national media relations in Rice University's Office of Public Affairs.