As one student put tape in his mouth to secure string to his model aircraft, another group sent smoke rings wafting through the air at the Mechanical Engineering Design Expo on Tuesday.

More than 50 engineering class projects, including a bicycle-powered cell phone charger, a solar-powered medical cooler and a bubble car, were on display in a packed Howe Hall to show off the work of five mechanical engineering design classes.

“We poured our blood and tears into this project all semester long, so it’s a great opportunity to showcase our work,” said Chloe Dedic, a senior member of one of the teams that helped design the Bubble Car.

More than 200 students got the opportunity to explain what they designed and why to ISU faculty and peers during the expo. This helps to prepare students for their careers when they will be asked to pitch their designs and ideas to the decision makers of a company.

One team from ME 423, Creativity and Imagination for Engineering and Design, created a plan for a mobile app for students looking to enjoy their adventure at Iowa State. The app includes an interactive and extensive list of adventures that students can choose from while attending Iowa State. Examples from the list include getting a picture with Cy, campaniling and making it into the Iowa State Daily.

One group member of the “Choose Your Adventure” app team, Paul Trieu, explained how their teacher directed their efforts.

“As soon as we got an idea, we wanted to go do it, and our teacher had to kind of pull back the reins a little bit and keep us focused on the design aspect instead of the production,” he said.

For graduating seniors, this event gave them the opportunity to wrap up their undergraduate experience at Iowa State and show some tangible evidence of their education to the public.

“Having to show off your work adds some accountability to your project because you know that you will be showing it to everyone,” said Jacob Karasch, another group member and senior in mechanical engineering.