We made an engineering design experience for kids and families attending the USA Science and Engineering Festival Expo. We made a set of small catapults and targets. The cool thing is that the catapults have three degrees of freedom — that means that kids can easily change how they work — so they can change where the cup is on the launch arm, where the rubber bands are attached, and the location of the stop (the thing that the arm hits, causing the ball to fly). It means that every kid who came to our booth could systematically redesign the catapult to do a better job of hitting the target.
But the story is not just about the catapults themselves, it's about the experience. Our booth was unique at the festival in having a coherent experience designed and delivered by engineering undergraduates. The goal is for children to come away from the booth understanding that engineering design is an iterative process that uses mathematics and science to address a need. And they learn this by experiencing the process. Kids first got to take a shot with the catapult, then spent some time with one of the students discussing how they would change the catapult for it to work better (for the older ones, assisted with some graphs showing the relationship of trajectory and arm length) and then after changing aspects of the catapult, the kids got another more successful try at the target. It's a lot of fun, and we worked with more than 600 children and their families at the April 2014 festival.
We got started on this when Professor Margot Vigeant saw an announcement for the first festival back in 2009 and thought it would be a fun extracurricular activity for a multidisciplinary team of students. The first group designed and delivered an experience based on robotics design, then the second festival team taught about engineering design through bridge building. We've been at every festival since, always with something new and student-designed.
We plan to attend the fourth festival in April 2016. But in the meantime, we're hoping to take either this project or something else cool and interactive to the World Maker Faire in New York this September.