Scuba Diving Fin Prosthetic Project

The Iowa 3D Club has always strive to provide low cost prosthetics to the young and old all across the nation. We have dabbled in elbow-down prosthetics and contacted clients through the web using pictures for measurements but never before have we had the pleasure to work with someone in our own school backyard.

Erica Cole - a senior in the University of Iowa faced an unfortunate event 8 months back that resulted in the loss of a leg (below-knee) but still wanted to take on a scuba diving class she had enrolled in. We reached out to her and proposed a project to work alongside her to create a prosthetic scuba diving foot/fin that would be compatible to the prosthetic she uses to walk.

Once she had agreed to collaborate with us, we took 3D scans and measurements of her prosthetic foot, along with all the components it comprised of.

After that, we went straight to the drawing board and started multiple CAD iterations of the mechanisms desired for the ankle and the 3D prints for the foot. Our constraints were that the fin would match the height of her other foot when set to the 90 degree angle setting, and the titanium lock that fitted to the upper piece of her leg had to have a secure fixture with no chance of wobble or rotation.

We later used subtractive manufacturing means to create all metal parts (ankle) and feet skeletal structure out of aluminum rods and plates, and additively manufactured the foot itself using PLA plastic, ABS, and TPU flexible filament on the CR10-S4 3D FDM printer.

Over the course of three months, we attended Erica's classes and tested the iterations we had worked on over the week. We took go-pro footages underwater and analysed the behaviour of our iterations on Sunday meetings and branched out into teams to undertake the various tasks and improvements that had to be implemented for the next upcoming class. Through this, we tremendously improved our teamwork, modeling, and rapid-prototyping skills.

The deadline for this project was the spring break trip she was taking with the class to Florida. Despite not being able to come up with a design that would provide Erica with the ideal thrust, we still managed to prevent any rolling action she experienced without the extra foot for stability, as well as provided a respectable amount of thrust that allowed her to swim faster. We are still working with her outside of class to enable her to make swimming a regular activity to keep her body healthy and active.