First-year students build and use sensors in biology lab

Students in basic biology labs at Pitt-Bradford are learning about more than basic biology.

A STEM-Sense pilot program over the last year has introduced the use of basic programmable sensors for carbon dioxide and moisture into introductory labs. The pilot was made possible by a $16,800 grant from the Office of the Provost at the University of Pittsburgh to encourage instructional excellence.

Drs. Denise Piechnik, assistant professor of biology, and Matthew Kropf, assistant professor of energy science and technology, collaborated on the proposal after students in a class on automation and sensors taught by Kropf worked on a biology project that Kropf thought would work well for first-year students.

The two professors wrote their grant proposal to purchase sensors, laptops and Arduino microcontrollers, which students would program themselves for the different sensing tasks.

What makes the STEM-Sense pilot unique is that students are building their own sensing equipment, giving them a better understanding of how it works, introducing computer coding and saving money all at the same time.

The first basic lab tackled was that of measuring cellular respiration, which is traditionally done in one of two inexact ways - counting bubbles that emerge from the tip of a pipette containing yeast and using those to estimate the respiration rate or capturing the gas using a balloon and measuring its diameter.

“It's incredibly frustrating,” Piechnik said of the old method. After programming their Arduinos with the help of Kropf, students could measure instantly and directly.

“We turned a guesstimation into an accurate data collection,” Piechnik said.

Dr. Mary Mulcahy, associate professor of biology, teaches the Biology 101 lab where the sensors were used. Once students could measure more accurately, they could take other measurements such as the rate of respiration and quickly and clearly see the difference between the respiration of yeast, peas and even humans, she said.

Students can also now measure changes in those rates due to reproducible changes in conditions, such as temperature, energy from sunlight or the amount of oxygen present. That, Mulcahy said, opens up the possibility of students doing their own original research using the sensors, which is just the kind of opportunity Pitt-Bradford is trying to provide for undergraduate students.

A second lab for Biology 217 allows students to measure the amount of moisture in soil. Piechnik has students plant varying numbers of radish seeds in the same size pot and has them predict how competition among the plants will affect the amount of moisture in the soil.

“Students really enjoy this work, and we consider this project a success because it generates interest in the STEM fields,” Piechnik said. “Many students have developed further interest and have taken Matt Kropf's course on Sensors and Automation.”

Piechnik has presented the project to other educators at the Annual Meetings of the Ecological Society of America and the Association for College and University Biology Educators.

In the coming year, Piechnik plans to survey students about how the STEM-Sense project helped them learn in order to gather evidence to improve teaching with the sensors.

She also plans to pursue a new grant that would allow her to collaborate with faculty from other schools to develop and share laboratory lessons.

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