Through User Observation, Performance Testing, Design Review and general feedback from the client and our fellow students, we ensured that our final design meets the main criteria that the client has emphasized. However, there are ways to make our TheraClip prototype better which were not feasible within the scope of this project. One of the possible improvements includes mass manufacturing our prototype using injection molding. It would make our prototype less expensive, quicker to produce and stronger than a 3D-printed TheraClip.
The prototype TheraClip is more expensive than a mass manufactured one would be for several reasons: the most significant reason is scale. As scale increases, production would get much cheaper. The materials could be bought in bulk and the device could be injection molded. Injection molding would decrease the production time and thus decrease cost even more. With our method, the cost of production of a single piece of TheraClip is between $0.73-1.00, which was calculated by adding up the cost of all used materials and manufacturing processes and dividing it by the number of TheraClips that could be produced with these resources. The cost of mass manufacturing TheraClip would likely decrease to about $0.20.
Strength is also a limitation of our current prototype. Our 3D printed TheraClip is currently strong enough for normal use, it passed out Performance testing and we decided to stick to this manufacturing method.We are unsure about its long-term performance: 3D printing only fuses a portion of the plastic together resulting in slightly weaker final material, while injection molding melts all of the plastic at once resulting in a uniform and homogeneous material, which would be stronger and more durable.
Injection molding also leaves a much better surface finish compared to our current method of production, 3D printing. In order to closely replicate the surface finish of injection molding we used XTC-3D, a surface finishing chemical for 3D printing. This currently uses a large percentage of our current budget and would not be necessary if TheraClip was mass manufactured.
As mentioned before, we could not use the injection molding technology for our design as it was outside the scope of this project. However, if we were to have more time and budget, we would definitely try to improve our current design by mass manufacturing it. According to our approximations, about 10000 people undergo physical therapy in the state of Illinois, and use three types of bands with different resistance, we would produce about 100000 TheraClips to meet the needs of these people for the upcoming 3 years.