El Medallo Bionic Arm

El Medallo is the world's cheapest-to-fabricate open-source bionic prosthetic. Created at eNABLE Medellin, the mechanical design of the device is a variant of the Kwawu Arm (by Jacquin Buchanan). 

This design features two different grips, a pinch grip, and a power grip, each activated by EMG sensor signals from two unique muscle contractions. These two unique grips are achieved by altering the timing of two servo motors controlling the fingers.

A step-by-step guide is provided in the documentation for this model, and anyone with basic electronics and 3D printing experience can make this. The estimated fabrication time from start to finish is approximately 80 hours. If creating a custom fit insert, add another 10 hours; this will be longer if you are unfamiliar with Fusion 360. This estimate includes file preparation, sourcing parts, soldering circuitry, calibrating the EMG sensors with the patient, and assembly. This time may be longer if you need to alter this prosthetic for a particular patient or if the prosthetic does not fit in the first attempt.

Files and Resources:

STL Files: Link

Instructions: Link

Parts List: Link

e-NABLE Device Color Customizer: Link