Our brainstorming process started with an objective tree , where we outlined our goals for the project. We created our first set of sketches and evaluated them using criteria based on these goals . We ultimately chose the gripper design (\for its versatility, since it could be used for a wide range of small objects unlike a card holder.

Despite it being our favoured design, it still needed many improvements and refinements. The design was refined to use gripper arms attached to gears which would rotate using a small motor to open and close, this refinement is shown in the first prototype (Figure 3). After discussing with the science students, we finalized a list of further refinements and improvements: Remove the brace, as the client expressed disliking them and the hassle of removing and putting on the brace would likely be more difficult than just picking up an object with their hands. Research all the electrical components we will need and their dimensions. Design a compartment to hold all the electrical components.

Decide how the device will be operated (button or switch)

While researching, we found that the components we needed were fairly large. This led to our second prototype shown below. At this point we still could not decide how to arrange the components in a comfortable manner, and we could not complete the refinements and improvements listed above. After discussing with the science students and TA’s, we ultimately realized that using electrical components caused more problems than it offered solutions. It made the design larger, heavier, and more difficult to repair while only offering ease of operation in return. This led to us brainstorming ideas for a purely mechanical gripper.

We created sketches for three new designs and evaluated them together. The first design (Figure 6) would use a string to rotate the gripper arms, which we decided might put too much stress on the finger pulling the string and could be difficult to hold. The second design used two racks mounted on opposite halves of a container to rotate two separate gears and would use springs to hold the gripper closed. We liked the idea of using a squeezing motion, but we decided two racks would be too complex and difficult to assemble. The third design also used a rack, but it only rotated one gear to open and close the gripper. We decided to combine our second and third designs by using the one rack system but also using the two halve design operated by a squeezing motion.

The third prototype is very similar to our final design (Figures 1 and 2), only missing the foam and spring. It also used gears glued to cardboard and a wooden rack instead of our final laser cut components.