Engineering students at Montana State University demonstrated their ingenuity Thursday, showing off machines they created to do everything from mining moon rocks to purifying water for poor villagers in Haiti.

At MSU’s annual Engineering Design Fair, 24 teams of seniors showed off devices they’ve been designing and building for their final year “capstone” projects. Another 36 teams of juniors showed posters of projects in the design stage.

One team of seniors created a device to detect minute impurities in water, with the unwieldy name “Modification to Surface Plasmon-Polatron Based Optical Sensing System.”

“It was stressful, but I learned a lot,” said Tou Vang, 23, an electrical engineering student from Missoula.

Most of the time, engineering students learn in classrooms, Vang said, but these projects were more concrete. “This is what you’re doing in the real world – not working for a grade or degree but for a client or a goal.”

The Lunabotics team of eight students built a moon-mining robot for a NASA competition at the Kennedy Space Center, where they’ll compete against 60 other college teams in May. MSU won the competition a couple years ago by creating a lunar backhoe that could dig up the most dirt fastest.

This year, the prize will go to the lunar robot that can not only dig up simulated moon dirt, but also navigate an obstacle course and “think” on its own. The students dubbed their entry “Montana ALE,” for Autonomous Lunar Excavator, said electrical engineer Bethany Higgins. It has little Bobcat logos etched into its metal wheels.

Another team built the MSU RoboSub, a robot about the size of a vacuum cleaner that can be programmed to swim underwater, explore its environment and make decisions for itself. Students showed a video of the RoboSub in action in MSU’s swimming pool. They will compete in a naval research competition in July.

Javian Blake, who came from Jamaica to study mechanical engineering at MSU and endured a lot of Jamaican bobsledding jokes in the process, said he and his RoboSub teammates got a sense of satisfaction from designing it from scratch. Cathy Bothwell, a mechanical engineering student, said they got to put all the basics they learned in class to practical use, and they also had to keep learning.

Mechanical engineers Cliff Davis and Presten Swenson came up with low-cost solutions to a big problem at Bobcat Stadium – how to get snow off seats quickly before football games. They contacted the New England Patriots pro team, and then worked up a tarp to cover folding Booster seats and a snow chute for faster snow removal from bleacher seats.

One team of five juniors designed a way to purify water for a school in rural Haiti, which a group of MSU civil engineers is working on. They designed a stationary bicycle to generate electric power and operate an ultraviolet light that can kill bacteria. Scott Byrnes, an electrical engineer, said it can not only produce 1,000 liters in 20 minutes, but it’s also designed to be theft-proof and something the villagers can operate themselves.

Rob Maher, electrical and computer engineering department head, said the great thing about the projects is that “We don’t know the answer – they have to come up with a unique solution.”

Most of the teams include students from a variety of disciplines. “That’s the way the world is now,” Maher said. “The problems we face are so complicated; we need a lot of expertise.”

Gail Schontzler can be reached at gails@dailychronicle.com or 582-2633.