Projekt · Jun 2026

Bionic Hand Controlled Through Computer Vision

Remixed Bionic hand steered via MediaPipe hand-tracking, Arduino Uno, and SG90 microservos.

This project is a personal remix of InMoov, the world's first open source prosthetic hand, originally designed by French sculptor and designer Gael Langevin. Langevin has worked with major brands for over 25 years, and he started InMoov back in January 2012 as a personal project. It's since inspired other open source prosthetics projects like Bionico and E-Nable.

For this build, the original InMoov hand geometry was remixed and redesigned in Fusion 360, with new joints custom fit for the specific servos being used, then 3D printed on a Bambu Lab printer.

Control system: The hand is steered in real time using Google's MediaPipe Hands library, which reads hand landmark positions from a webcam feed. Those readings get sent to an Arduino Uno, which converts them into high and low signals that drive small SG90 microservos, and those servos mimic the movements of the tracked hand. The control logic is written in C++ using the Arduino IDE.

Mechanical actuation: Each finger joint is tensioned by an elastic band anchored at the back of the joint, which keeps the finger extended by default. A fishing line runs from each servo to the corresponding fingertip. The servo rotates 180 degrees to pull the line and curl the finger closed, then rotates 180 degrees back the other way to release the tension and let the elastic band pull the finger back open.

Design note, inverted mapping: The hand currently mimics inverted movement. So when the operator's palm is open, the robotic hand closes, and vice versa. This isn't a mirroring bug, it's an intentional design choice. Since a relaxed, open palm is the natural resting state for a hand, mapping "open" to "servos relaxed" just made the control logic simpler to build and tune. Making the mapping mirror real hand movement one to one, open equals open and closed equals closed, is a straightforward software change if a more intuitive or realistic feel is wanted later.

A few known limitations id like to improve:

SG90 microservos were used mainly because they were what was on hand at the time. Stronger, higher torque servos would give the fingers more grip force in future iterations. The elastic bands on the back of the hand don't give the smoothest movement. They can get sticky and catch a bit, so the finger release isn't always fluid. This is an area that could use improvement, maybe through a different return mechanism like small springs or a low friction band material.

Mechatronics
Robotics
Arduino
Fusion360
3D Printing
Computer Vision
Machine Learning
Electronics