CRETE - When you think of a project an engineering student might take on, you probably envision something involving gears, wires or scaffolding.
But how about designing and building a brand new leg for a dog who was born with only three? A partnership with a woman and her dog in the Crete community helped give student engineers at Doane University some "paws-on" experience doing just that.

Meet Nugget, a mini goldendoodle who was born without her front right leg. She’s more than capable of walking normally now, as she prepares to celebrate her second birthday later this month, but that might become more of a challenge for her as she gets older – so Nugget and her human Diane tapped into their connections at Doane University, and asked a group of mechanical engineering students if they could develop, design and build Nugget a fill-in right leg. 

“Our goal was to make life better for the dog, especially as it ages – give it something to help take some of the weight off the other front leg,” said Cale Stolle, associate professor of engineering at Doane. “It’s a bit of an extreme circumstance, and from my perspective as a professor it gave us a more challenging project. One of the biggest issues here is we have to design something that not only is comfortable for the animal, but it’s also something that is sustainable, durable, low cost, and lightweight.” 

“It’s pretty cool to be involved in something that’s relevant to you,” Doane junior Cayden Miller said. “Most engineers will design and make buildings or something, and not only is this significant to us...this is touching because I have a three-legged dog myself, so this is something I can use myself with my dog.” 

“It’s fascinating. If you tell me two years ago when I was thinking about Doane that I’d be designing a dog leg for an actual dog – something you do later on in life – I was amazed,” Doane sophomore Lucas Christensen said. “It’s definitely one of the coolest projects I’ve ever done, and I’m very happy I was able to do this. I never thought something cool like this would come my way.” 

A group of eight students in Stolle’s second-year engineering course split into two teams to attack this highly unique assignment, and over the past few months their initial prototypes evolved into these prosthetics. Now comes the all-important application period: strapping the devices on, and seeing how Nugget adjusts to her new leg.  

Complicating this challenge further is the fact that most animals a veterinary doctor would consider building a prosthetic for would be missing the limb in question completely, whether through an accident or an amputation or otherwise. But Nugget was born with part of that right leg intact, so the students had to develop a design that’s tailor-made to this particular canine customer.  

“We had to make a pocket in the shoulder so the nub itself could actually fit and be comfortable, and not get tangled up in anything and get damaged,” said Miller, a junior from Texas who is one of the team leads. “We also wanted the prosthetic to not beat the dog every time it takes a step, so part of the foot is bendy, so it takes up some of the shock every time it takes a step.” 

“Originally we had more of an athletic fit like you see with a lot of track stars that are missing a leg, they have kind of a half shape; but we figured for the dog, we don’t want it to get caught on anything, so this flexible ‘O’ shape works a lot better,” said Christensen, a sophomore from Malcolm who led the class's other crew. “We slimmed down the design as much as we could, made it as lightweight as we could. We designed this socket where the stump is able to just rest inside, and all these pockets are just to increase air flow to keep it cool for the dog and so sweat doesn’t get trapped in there.” 

All that adds up to create a highly unique engineering endeavor, one that also incorporates other disciplines like biology, veterinary medicine, psychology, kinematics, ergonomics, community relations, and public speaking – giving these Doane students a breadth of knowledge their professor says will serve them well once they move on.  

“If we just focus on the one aspect and say this is all you’re ever going to focus on, unfortunately that really does a disservice to the students overall,” Stolle said. “For this project specifically, students are having to take something that is a living being, and apply something that is cold, hard plastic and mount it to it – mesh the worlds of how real life interacts with something that they designed in a 3D modeling software in a computer upstairs. All of these aspects build under the greater picture, so yes there’s engineering work done, but there’s so many other facets that have to be done in tandem to the engineering project to make sure that it’s successful.” 

After this week’s hands-on session with a willing test subject, the students will get one more week to modify their designs to see if they can design a functional new leg for Nugget before the semester ends. From there, if there’s some success, Stolle says there’s every chance other animals could serve as test subjects for other Doane students sometime in the future. 

“We took this on a labor of love for someone in the community because we have engineering students who are extraordinarily capable, and giving them a project that is directly benefitting someone in the community is just something that I really enjoy,” Stolle said. “I know our students would love to do this again – they’ve already been asking me if we’re going to be doing this next semester.”