A Green Light for Learning

By Dustin Renwick

Karoline Johnson shows off the air sensor.

Karoline Johnson shows off the air sensor.

Movies depict bad breath as a green haze, but anyone’s breath can change a new prototype air sensor, developed by EPA researchers, from blue to green to red.

Karoline Johnson, an EPA student services contractor, worked with Gayle Hagler, an EPA environmental engineer, to design an interactive air sensor that provides an opportunity to share science and technology with the public.

Here’s how it works: When a person breathes into the box, the sensor measures the amount of infrared light absorbed by CO2. This measurement is converted into an electric signal that a computer board translates into light. The top of the sensor changes colors based on the presence of increasing amounts of CO2 we expel each time we breathe.

The sensor provides a visual starting point for broader science discussions by transforming abstract subjects into an interactive, physical display.

“We realized there are a lot of different applications for what you can teach the public,” Johnson said. She said the sensor deals directly with air quality and climate science, but it can also serve as a  tool for talking about topics such as human health, computer programming and optics.

Low-cost, portable sensors have the potential to change air quality monitoring by allowing anyone to measure air quality with calibrated devices that require little training and provide real-time data. Current sophisticated air monitors produce accurate results but scientists can’t easily move these large monitors and the costs are prohibitively high for the average person.

Plenty of challenges remain for the next-generation air sensors, including proper calibration, where the data will go, how the data can be used.

But the promise remains. A network of cheaper sensors could give students, community leaders, scientists and university researchers a more complete picture of air quality.

Johnson is currently working on a sensor curriculum and kits that teachers and students can build in their classrooms.


About the Author: Dustin Renwick works as part of the innovation team in the EPA Office of Research and Development.

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