Chemical engineering students place third in design challenge

Undergraduate students from Texas A&M University’s Artie McFerrin Department of Chemical Engineering secured third place at the regional American Institute of Chemical Engineering Chem-E-Car Competition in March. 

Hosted by the Southwest Student Regional Conference, the competition has teams design and build a small car powered by chemical reactions, competing in regional competitions and demonstrating precision, innovation and teamwork in one of the discipline’s most rigorous student design challenges.

“We’re very happy, because this stuff is just so finicky,” said Lisette Torres ’28. “One small thing going wrong can take down the whole car. The car moving in the first place was already exciting and receiving third was a relief from all the time we put into it.” 

The 10-team competition took place at Texas Tech University. The ultimate goal was to build a chemically-powered car that could move 26.3 meters. The team’s car — Maroon Pearl — covered 13.3 meters, the third-best performance among all entries.

“Everything is chemical reactions,” said Daniel Behringer ‘28, Chem-E-Car chair. “The propulsion reaction makes the motor spin, and the timing reaction tells the motor when to stop. For the timing reaction, we used an iodine clock reaction, where solution A mixed with solution B. At a certain point, it turned the solution color black. A photoresistor installed in the car picked up the change in luminosity, so when the solution turned black, it cut power to the motor.” 

There were two rounds of the competition. In the first, the car did not move, triggering the team to rebuild the entire battery from scratch in a 20-minute period. 

The battery uses an electrochemical reaction between aluminum and air to produce a voltage, turning aluminum into aluminum hydroxide while oxygen is reduced in the solution. By using 14 identical units, the team generated enough voltage to power the motor.

Eventually, the team ended up double-wrapping the paper towels, which is what made the car run on their second attempt, indicating internal shorting in the previous battery. 

“It was a long road to get a working battery,” said Juan Pablo Alvarez ‘28. “We dabbled in wet cathodes and catalysts, but eventually pivoted to a simpler design. We learned so much this year and got so much momentum out of this competition, and I feel like we’re making big changes to the whole structure of Chem-E-Car procedures.” 

The team featured multiple committees that oversaw a different aspect of the car’s operation. The mechanical committee designed the car and 3D-printed all of its parts. The controls committee integrated the propulsion system with the timing reaction to get the motor to stop.

“The propulsion committee generated 12 volts for the motor with a battery made from at-home supplies,” said Tiago Sousa ‘28. “It was a few pieces of aluminum foil that we wrapped in a paper towel, which we then wrapped in steel wool and submerged in electrolyte solution. We used potassium hydroxide.” 

The overall idea came from a baseline of what the Chem-E-Car team did last year and was implemented while performing structured upgrading at the same time. 

What the team took away from the competition was the importance of full-scale testing and understanding each part of the car. 

“The key was teamwork,” Behringer said. “We had people that were willing to work together efficiently, and do what was necessary to get the car done.”