Gould Academy senior Demetri Maxim is working on using skin cells to grow kidney tissue, taking steps toward a new treatment for kidney disease.

He is among 40 U.S. teenagers who have been named finalists in the prestigious Intel Science Talent Search, which recognizes rising stars who have done notable original research. All 40 will be in Washington this weekend competing for $1 million in scholarship awards, including three top prizes of $150,000 each.

A public exhibition of projects will be held Sunday, March 13, and the top winners announced Tuesday, March 15.

Eighteen-year-old Maxim has created a method to bioengineer kidney tissue from a patient’s own cells, work that he hopes eventually will mean that scientists will be able to grow new kidneys for people suffering from chronic kidney disease, so they won’t have to wait for an organ donor or risk their bodies rejecting a donor’s kidney.

“I was essentially growing kidneys in a cell, that’s how my friends say it,” said the student at the Bethel, Maine campus.

The project is personal for him. He has polycystic kidney disease, a genetic condition that leads to kidney failure. His grandfather and his great-grandfather also had the same condition, and his mother nearly died from it; a kidney transplant saved her life.

“I have the same disease that my mom does, so someday I’m going to need a kidney,” Maxim said.

Maxim said he had to teach himself a lot of basic research skills by reading papers and taking online tutorials. But last summer, after sending out countless emails to researchers, he found a Harvard professor who was willing to serve as a mentor and give him access to a real lab. The professor, it turned out, had years earlier diagnosed Maxim’s mother with polycystic kidney disease.

Maxim used skin cells to grow stem cells using a lab protocol developed by Nobel Prize-winning scientists. He used those stem cells to grow kidney cells. And then, to create tissue, he transferred those kidney cells onto a three-dimensional structure. That 3-D structure was composed of de-cellulized mouse tissue, or mouse tissue stripped of all its cells.

“And that’s never been done before,” Maxim said. “It’s one thing to have cells in a dish, but it’s a totally different story to have functional tissue.”

Maxim then tested the kidney cells by transplanting them into a live mouse with a functioning kidney. He found that the cells survived and became integrated into the mouse’s organ.

There’s still a lot of work to be done before human patients can receive organ transplants grown from their own cells. But Maxim plans to stick with it when he goes to college next year.

Meantime, he’s been helping his high school create a research program for other aspiring young scientists. He applied for grants and solicited donations that allowed him to build a lab at the school, and he’s been teaching freshmen and sophomores how to do basic lab work.

Maxim said it’s difficult to find other students his age who are interested not just in skiing and soccer and music, as he is, but also deeply interested in science. He said he was shocked to be an Intel finalist, and is excited to spend time with the other 39 finalists. “You’re with your real friends for a week,” he said. “That’s what I’m most looking forward to.”

It can be deeply humbling to scroll through the other project descriptions and biographies. And it also can inspire hope: These young people are looking for answers to some of the world’s most intractable problems, and they’re making important progress. They also have interests outside of science, from dancing to skiing to soccer and music.

Another finalist has studied ways to make plastic decompose more quickly. And a third invented a device to diagnose lung diseases in developing countries. It’s made out of $35 worth of materials — patent pending.

Maya Varma, 17, created an inexpensive device to diagnose and monitor chronic lung diseases, a project she hopes will save lives in developing countries where such a device — called a spirometer — might otherwise be inaccessible.

Hospital-grade spirometers cost hundreds or thousands of dollars, Varma said. Her version: $35.

“People can’t afford this expensive equipment, and I decided to do something about it,” said Varma, a high school senior from Cupertino, Calif.

Doctors can use data from Varma’s invention to diagnose and manage chronic pulmonary illnesses such as asthma or emphysema. Patients blow into the device and a smartphone app, which Varma created, analyzes the results.

Next, Varma wants to test the device on a wider scale, and eventually she’d like to take it to market. Last year, she was featured in Popular Mechanics magazine as one of “15 young innovators who are already making a difference.”

She plans to study biomedical engineering in college.

Augusta Uwamanzu-Nna, 17, figured out how to create stronger cement seals for undersea oil wells by adding a nano clay ingredient, a project motivated in part by the 2010 Deepwater Horizon oil spill in the Gulf of Mexico, thought to have been caused in part by problems with the offshore well’s cement mix.

Uwamanzu-Nna, of Elmont, N.Y., first became interested in cement when she learned how energy intensive the cement industry is, accounting for up to one-seventh of human-caused carbon dioxide emissions.

“It was just so mind-blowing to know that one industry can cause these many emissions,” she said.

The more she learned about cement, the more she noticed its critical role in modern society. It is ubiquitous, she said, yet no one ever seems to talk about it. “It’s the second most consumed material after water. It’s like you would never know that,” she said.

Most young stars in science aren’t studying cement, said Uwamanzu-Nna. They tend to gravitate toward research in biology, chemistry, biochemistry, she said, and often focus on problems related to human diseases. And at the beginning, as she struggled to find her footing in the world of cement, she felt as if some of her peers looked down their noses at her.

“Starting off on this unconventional path, there’s people who look at you differently,” she said. “They’ll have their snide remarks because you’re doing something different.”

Eventually she found a mentor at Columbia University who gave her access to the high-tech machinery she needed to test the properties of different cement mixes. And she found success in the world of high-level science fairs, a fact that she attributes to sticking with her interest in lowly cement.

“You know it’s not bad to do something different,” Uwamanzu-Nna said. “You might come across obstacles, but it’s important to keep going, because all your hard work and efforts will not be in vain.”

She plans to study engineering in college, with an eye toward contributing to a more sustainable world. But science is not her only thing: The daughter of Nigerian immigrants, she founded a dance group that raises funds to benefit communities in Nigeria. She also edits her high school newspaper and sings in her church choir.

Thomas Colburn, 17, studied how to make plastic shopping bags and milk jugs decompose more quickly by adding particles of titanium dioxide.

Adding titanium dioxide meant the thin plastic used in shopping bags would break down within six months, instead of five years; the thicker plastic used for milk jugs would break down in 23 years instead of almost 270 years.

He was motivated by the litter he saw while running trails around his home in Oak Ridge, Tenn.

“When I see littered objects in the beautiful terrain around my community, that’s the inspiration I drew upon for my project,” he said. Colburn runs cross-country and track for his high school and also plays in the school’s marching, jazz and symphonic bands.

He said he’s been dreaming up possible inventions ever since he was a little kid. As he got older, he realized that he could combine his creativity with engineering to solve problems. Earlier in his high school career, he studied hydrogen fuels and how to make biofuel from invasive plant species.

“My plastic experiments were a progression of my developing skills in the scientific method,” he said.

He’s interested in studying chemical engineering and doing energy and environmental research in college.