What it is

Mirror Hand is a bit of a strange project. It's a robot hand that copies whatever my own hand does in front of a webcam. It's one of my early projects, from when I was just getting into Arduinos and electronics: small motors, how electrical connections work, that kind of thing. I made it at home, outside of school.

Why I made it

I saw someone post something like this on Instagram, so I decided to build my own version. I had a few parts lying around, ordered some more and tried to recreate it with what I had.

There was no real practical purpose behind it. I mainly wanted to test things and find out how all of this works.

When I showed it at school afterwards, they really liked how I'd gone about it. I didn't have great materials, but I found creative ways to solve things with what I did have. They said it showed I understand how things work and can find my own way to build them.

How it works

I used an Arduino and servo motors to move the hand, and I made hand tracking software on my computer in Python. It reads the webcam and finds 21 points on your hand. For each finger it works out how far it's bent and sends that to the Arduino over USB. The Arduino then turns five servos, and each servo pulls a string that runs to a fingertip, so the finger curls. That way, whatever your hand does, the robot hand does too.

How I made it

I first made it out of cardboard, which was enough to test everything from the camera to the fingertips. After that I had it 3D printed, with hinged fingers and a forearm that holds the servos. Together the servos needed more power than USB can give, so they run on a computer power supply.

What I learned

I never took this project any further, so it isn't really finished. But I learned a lot from it: how Arduinos and small motors work, how coding works and how all the wires need to be connected. I also learned to start simple with cardboard before making something properly, and to keep the tracking, the communication and the mechanics separate, so you can quickly see where a problem is coming from.