2009 Future City Competition in a ballroom in a Washington, D.C. hotel.
Abby Sharp, Tom Krajnak and Wyatt Peery from Bexley Middle School in Ohio stand before a packed audience of their peers, teachers, parents and judges to present their entry: Novo Mondum.
The trio is among 38 teams - whittled down from 1,100 - that won regional Future City events and were invited to Washington to compete for scholarships and special awards.
The theme of this year's competition is water.
Each team had to design a model city, build it to scale with recycled materials and defend their concept before a panel of judges.
Asked by a judge to describe one new water recycling technology, 14-year-old Tom Krajnak handles the question as if he were a civil engineer.
"The microbial fuel cells that we use charged bacteria which - when they consume waste - generate energy, which helps power the electrical systems, such as pumps in our water system."
Students from Valley Park Middle School in New Jersey have designed their "City of Hope" - located along the banks of China's Yangtze River - with abundant, clean and safe drinking water. What makes it work, says team member Jack Maguire, is the Molecular Containment Disassembly, or MCD.
"It uses nano-bots to disassemble physical and chemical contaminants. [It also] uses carbon nano-tubes filters."
Team member Bobby Matts adds, "It lets us use water, but not waste any. And, also we have green roofs, which are gardens on top of our residential buildings. [They] pre-filter the water and give residents a place to grow food."
In their 22nd-century design, buildings would be coated with a solar polymer to collect the sun's energy. Plants would be able to grow directly on the walls. And people would travel in pressurized aquatic vehicles using hydropower tapped from reservoirs. Team member Runhe Li expects one day these concepts will be put to practical use.
"We designed this city so that everything in our city would be able to happen in the future, because we are in the year 2175, and we believe that everything will be able to happen by then."
Young engineers at Al-Hadi School of Accelerative Learning in Houston, Texas locate "L'ile Verte" - French for "green island" - between the Pacific Ocean and the mountains of eastern Australia. Student Amirpooya Dardashti explains that the city uses a hydro-mill to manage water, captured from the atmosphere and purified into drinking water.
"We also have other sources of conserving water, such as our Gray Water Recycling Brac System," he says. "It filters and pumps waters from showers, drains and bathtubs, and then it reduces average potable water consumption by 50 percent."
The students have turned recycled computer parts, empty candy boxes and tissue paper into a city of the future. It includes the PRT, or Personal Rapid Transit system, that runs on renewable energy, and which Future City judges honored with a special prize for green innovation. Amirpooya Dardashti says it is one feature he would like to adapt to his home town.
"We all live in Houston, Texas, and the two problems in Texas are that it is dirty and a lot of pollution and also a lot of traffic."
Al-Hadi science teacher Nilofer Momin says projects like these have the power to change lives.
"They actually came to know what engineers do for the city," she says.
Student Ali Ahmed appreciates those services.
"They put scientific knowledge into practice," he says.
Classmate Yasmine Sanai says she learned that girls can be engineers, too, and "have a good life and [a] good career."
The Future City Competition is sponsored in part by the National Engineers Week Foundation, a consortium of professional and technical societies and major U.S. corporations, which promotes the development of new talent for tomorrow's workplace.