Prosthetic Claw Prototype
Dec 2023
GOAL: build a prosthetic prototype
SKILLS: CAD (OnShape), python programming, use of microcontroller (arduino), gear design, use fo arduino servo library, signal filtering, use and placement of ECG/EMG electrodes, collaboration
This claw reads electrical signal from ECG electrodes attached to the user's arm, filters them, and then opens and closes based on the signals. It uses a servo motor for the basic movement and an Arduino for control.
claw.cpp Code
claw.cpp.pdfFabrication
The claws and base are 3D printed from an OnShape CAD model.
The servo motor slides into the rectangular hole in the green base, and is supported by a stand behind it.
The blue pieces slide into the slot in the green piece for easy assembly, and stabilizes itself.
The servo motor is attached to one of the gears, such that the rotation of that gear causes the other to move; because the claws are directly blended into the gears, this creates the opening and closing motion.
We used hot glue on the end of the caps to provide some extra grip.
Things to adjust in the future:
adding bluetooth/internet communication so everything isn't connected by wires
making the claw more hand-like
adding more advanced signal filtering
making an attachment to fit over the other hand
making a sleeve to keep the electrodes stable and in a consistent position
using the red electrode as a calibrating electrode so that there can be more movement