We’ve continued to work on landing on a finger design that we think will be the most viable in our final upper limb prosthesis design, Krobohand.
As we showed in our last blog, we had a complete redesign of the finger, with many changes that proved to be extremely beneficial in practicality, but also some that were not as beneficial. Some major changes we plan on keeping is the method of attaching the flexor tendon to the linear actuator. By merely wrapping a double channel in the tip of the finger, we will be able to bypass any extra parts or complications for actuation. The two channels will meet at the base of the finger in the palm, where the flexor tendon will join into one strand, and attach to the linear actuator.
Another aspect of the redesign we plan to keep is some form of finger tip. Our original design doesn’t have any kind of tip on the first segment of the finger, so picking up smaller, objects, such as the ultimate test of a penny on a flat surface, would be extremely difficult. Though the redesign’s tip probably won’t be exactly what we’ll land on, it’s a step in the right direction. Ethan was able to speak with Dr. Reinkensmeyer, and he had suggested some form of tip as well, so we’ll definitely be designing that into the finger.
Other aspects we don’t plan on using that were part of the redesign include joint design, lateral joint design, and integrated tendon design. So far, our original design had more viable aspects of these three designs, so we’ll keep what we have on that front.
Apart from the finger design, Cameron is currently working with the electromyography equipment that we recently received, and we will be meeting soon to figure out the ins and outs of making the sensors work efficiently and effectively.
Next blog update, we hope to have data from some tensile and three-point bending tests from the Instron machine. We’re waiting on a response from Steve Weinstock, the Lab Manager at Engineering Tower, on when we can bring in our prototypes to test until failure. We’ve printed four prototypes specifically to have destroyed for testing purposes, and are excited to share our results with everyone.
-Krobohand Group