Project Creation Date: July 2020 - August 2020

<aside> 🎓 Skills Learned:

• [ ] Basics of electronic circuit design
• [ ] C++ Arduino programming
• [ ] Troubleshooting
• [ ] Persistence </aside>

Project Overview

The goal was to create an animatronic hand that would mimic my own hand movements. This project required me to be resourceful with materials around my house to use as mechanical components and invest in an Arduino starter kit for the electronic components.

Below is a video of the robot in action:

https://youtu.be/VgUPK8VFOuI

Key Points

• Foam material was used for the bulk of the fingers and palm as it is lightweight therefore it will not be difficult for the servo motors to pull the fingers forward
• At first, the fish line connecting each finger to the servo motors were tangling with one another during movement. To fix this I glued pieces of straw to each finger “muscle”. This way the servo motors would pull the fingers with ease.
• When deciding the material to use as the “joints”, I needed to experiment for a while. The first idea was to attach rubber bands since they have the elastic properties required for the fingers to return to their previous position after movement. Unfortunately, rubber bands did not have the strength to hold the fingers up (as they are quite flimsy) and reach a failure point after a limited amount of time. The next option was pipe cleaners since they were stronger but I realized they missed the needed elastic properties. Finally, I chose my hair elastics as they met all the requirements; they were strong enough to hold the finger muscles in place, they possessed elastic properties and they are built to withstand use after a longer period of time.

After a month of building, learning how to properly make a circuit, and troubleshooting the Arduino code, I did it! I built my first robot and the journey was worth it. You may be wondering “How does this work?” The animatronic hand takes input from the flex sensor gloves and outputs movement in the motors. When the flex sensors are at their original position, they generate a steady resistance value in the circuit. Once the flex sensor is bent the resistance gradually increases. I programmed the Arduino to turn the servo motors based on the change in resistance. For example, if the resistance increases to 30 ohms, the servo motor will rotate 90 degrees in the clockwise direction. As a result, when I bend my finger, the flex sensor resistance will change to a certain value that allows the servo motors to ate just enough to pull the fishline wire connecting the animatronic hand and mimic my finger movement.

Though, this project is still a work in progress. The hands are glitching, which may be a result of unequal voltage distribution because of the additional resistors I chose. I intend to do more research and experimentation in the future to learn how to choose the right resistor values for this circuit.