CURRITUCK — Grape juice is ideal for creating a battery. That’s what three J.P. Knapp Early College High School students discovered when they entered the Carolina STEM Challenge.
Cammie McMahan, Angie Chen and Wyatt Fairbanks recently won first place in the challenge, a statewide competition open to middle and high school students.
Their challenge was to build a battery using only vegetables, fruits or fruit juices and strips of metal. They were judged by how much voltage their battery produced and the quality of their video presentation on the battery.
The battery produced “3.88 volts of direct current,” their honors chemistry teacher Crystal Schultz told the Currituck County Schools Board of Education at its June 30 meeting.
The students put copper cathodes and magnesium anodes in the grape juice and were able to use this battery to power an LED light, as well as a noisemaking device.
Creating the battery allowed the students “to really focus on that engineering part” of STEM — Science, Technology and Math.
The students experimented with potatoes, orange juice, oranges and lemon juice, McMahan said, but found the grape juice produced the most voltage.
While unsure exactly why grape juice worked best, Fairbanks quipped, “Grape juice just might be really, really good.”
He said that the magnesium was starting to dissolve, so the battery had a limited life.
The students are all ninth-graders — a rarity in an honors chemistry course, even at J.P. Knapp, Schultz said.
“They were definitely real go-getters (who) work hard,” Schultz said of the students, who were the only ninth-graders in their class and among just five total ninth-grade students in honors chemistry courses the past school year.
At traditional high schools, 11th-grade students typically take chemistry courses. At J.P. Knapp, because the early college high school is fast-tracked, her honors course is mostly 10th-grade students, she said.
McMahan, Chen and Fairbanks, “do really well in chemistry,” she said, and the competition provided them the opportunity to be challenged outside the curriculum, she said.
They worked on the “battery dilemma” during office hours and after school for about a month, she said, estimating that two weeks were dedicated to creating the battery and the rest of the time was spent creating the video submission.
The video could not be edited and couldn’t have cuts, to prove that it was authentic, so they had to explain the process and show the battery working in one take, she said.
The students received individual medals, and the school received a certificate, plaque and $200 in prize money.
The money is being used to purchase an electronic balance for the classroom that can measure the exact mass of chemicals.
“It’s a tool they would use in college, as well as in the workplace,” Schultz said, so it provides students with hands-on experience with “some equipment that may be out of reach otherwise.”
This will be the classroom’s second digital balance, because Schultz purchased one with the first-place winnings from last year, as well, she said. The STEM Challenge competition has only existed for two years, and J.P. Knapp teams have won it both years.
“I look forward to applying again next year,” Schultz said. The competition “really builds those future-ready skills so they’re prepared to solve problems that they don’t already know the answers to.”
McMahan said in an email that she plans to take biology, chemistry, physics and microbiology at College of The Albemarle, and is interested in a career in microbiology or genetics.
“This (battery dilemma) experience along with taking high school biology and chemistry this year prepared me for the United States Naval Academy STEM summer program, which I was accepted into and happily completed this summer,” she continued.
“I would also like to thank my wonderful teacher, Mrs. Schultz, for the great opportunity. She has been a great mentor and role model in chemistry, a field usually occupied by men.”