Ana Humphrey of Alexandria, who is a finalist in this year’s Discovery Education 3M Young Scientist Challenge, has submitted a project focusing on preventing the spread of disease. She is one of three Washington-area finalists. (Courtesy of Discovery Education 3M Young Scientist Challenge)

Katherine Wu, 14, takes an annual road trip to Florida with her family, where they usually visit an amusement park, her favorite so far being Universal’s Wizarding World of Harry Potter. It’s at least a 14-hour drive from their home in Montgomery County.

Katherine noticed that her mother would have to regularly check in with her father during those late-night highway drives, expecting a coherent reply that ensured he was still awake and alert enough to keep going.

Moments such as that sparked her idea for “A Driver’s Companion,” a small device that monitors a driver’s brain waves to proactively determine drowsiness and, in the event a driver begins to drift off, alerts them with audio and light signals.

A budding scientist and rising ninth-grader at Montgomery Blair High School in Silver Spring, Md., Katherine created a prototype of her device, submitted a video explaining the research behind it and earned a spot as one of 10 finalists in the 2014 Discovery Education 3M Young Scientist Challenge.

Students from across the country in fifth through eighth grades submitted videos about their scientific solutions to everyday problems, and finalists were paired with a 3M scientist mentor to help them fine tune their prototypes. The students work with their mentors to learn more about the scientific process.

Katherine is one of three Washington-area finalists, the other two coming from Virginia: Ana Humphrey, 13, of Alexandria, whose project focuses on preventing the spread of disease, and Jai Kumar, 12, from Loudoun County, who has developed a distinctive air-purification system.

Katherine said her project is the beginning of what she hopes is a career in the Science, Technology, Engineering and Math (STEM) fields. She wants to be able to use such work to make a difference.

“I really like how you can learn something and use that to help society,” she said.

For her project on proactive drowsiness detection, Katherine put together a prototype using a headset and a credit-card-size computer motherboard called Raspberry Pi. She then programmed an algorithm to read a driver’s brain waves and determine levels of drowsiness. Her father, Haibin Wu, said Katherine took an introductory online course in electrical engineering and computer science from MIT to help her with the project.

Katherine has been working with mentor Jesse Miller to develop the device. Miller, a product developer for 3M’s Food Safety Department, said that while other known devices meant to detect driver drowsiness rely on eye blinks, he said he believes Katherine’s consideration of brain waves makes her project stand out.

“It’s got a huge advantage on the stuff that’s out there,” Miller said, adding that he believes Wu should think about developing her prototype into a marketable product that could really benefit drivers. “It’s a pretty neat idea.”

Saving lives also is big motivator for Ana Humphrey.

Katherine Wu of Montgomery County is a finalist in the Young Scientist Challenge, thanks to her idea for “A Driver’s Companion,” which would monitor a driver’s brain waves for drowsiness. (Courtesy of Discovery Education 3M Young Scientist Challenge)

In an effort to prevent cholera outbreaks, Ana, a rising eighth-grader at Alexandria’s George Washington Middle School, developed a calculator that enables her to measure how much wetland must be planted in an area to reduce bacteria to safe levels.

The science competition touched on two things Ana loves: Making videos, and the field of science and engineering. When she got the phone call naming her a finalist, she had to put the phone aside as she screamed for joy.

“I tried to suppress it, but I’m not sure how well I did,” Ana said.

This summer, Ana has been doing more research and keeping in touch with her mentor Raha Been, a 3M senior research scientist who oversees the development of wound-care technologies. Been challenges Ana to practice problem solving.

“She does all the innovating herself,” Been said. “I don’t give her the answers.”

Been said Ana’s calculator could serve areas affected by hurricanes and could be helpful in developing countries at risk of contaminated water.

A global issue also inspired Jai Kumar’s project. Jai’s grandparents live in India, where high levels of air pollution often prevent them from opening the windows in their home.

This prompted Jai, a rising seventh-grader at J. Michael Lunsford Middle School, to make a solar-powered air purifier that ionizes air and traps dust in mesh before it can enter a home.

His experience in tinkering with electrical devices started when he was about 5, after his parents bought him an electronics kit. He would wake up early just to mess around with it.

“I have a really strong passion for science, math, technology and engineering,” Jai said. “It would be really fun if I can actually earn money for that.”

Jai has been working with mentor Kris Thunhorst, a senior research specialist in 3M’s Industrial Adhesives and Tape Division, and said he is grateful for her expertise.

The finalists are scheduled to present their projects at the 3M Innovation Center in St. Paul, Minn., in October. A grand prize winner will receive $25,000 and a student ad­ven­ture trip.