Riley Smith
This project began as an idea of a simple prosthetic hand that possesses humanoid movement in both the fingers/thumb and the wrist. As the hand has been developed the initial idea of a design has been tested through analyses of the structure of the hand. These analyses provided parameters on which to base the dimensions of the hand. The design of the project has taken place in the CWU Hogue Technology building, using the computer lab.
The construction process of the hand will begin with design of the hand components on SolidWorks, with iterative designs shown in the drawings. The hand itself will be comprised of 4 fingers and a thumb that all articulate. The individual fingers will be in 2 components, an angled upper joint consisting of the mid joint and fingertip, and a lower joint that connects the upper joint to the two piece palm. The forearm will be attached via a fixed wrist, where the articulation hardware will be contained. Fastening the joints will be various pins that will also be printed from the same material. The design of the forearm will house the components necessary to provide motion, but it is also intended to be material conservative since it is the longest part of the project.
In terms of general operation of the project, the hand is meant to be capable of gripping a can because of its pounds of pressure per finger, while also being able to articulate a full range from rest position (open hand) to a full closed fist inclusive of the thumbs function.
The benchmark prosthetic known as the Bebionic hand is constructed differently than the project because of the usage of carbon fiber in that hand, but in terms of motion and general shape, the project hand will move the same. The finger pressure capable on the Bebionic hand is around 10 pounds depending on the grip configuration. Though the project will not have those configurations, it will match the pressure per finger up to 7 pounds.
The initial performance of the project after construction is expected to be at 50% functionality or less, since the design of the hand will need refining to reach the desired functionality with a repeatability of motion in the range of 85%. Once the function reaches 100% of what is desired, then the repeatability factor of how often the motion can be repeated comes into account. Repeatability is meant to be a sort of efficiency of motion for the project.