Open-source CAD for a low-cost, body-powered prosthetic hand with a gear-based selective clutch that routes a single input cable to multiple functional modes. It accompanies our Humanoids 2026 paper, "Open-Source Body-Powered Prosthesis with a Selective Gear-Based Clutch Mechanism for Switching Grasp Types." This repository contains the CAD models for a body-powered, underactuated prosthetic hand featuring a gear-based selective clutch for discrete mechanical mode switching.
A sliding gear selects one output at a time. Inactive outputs are locked by fixed sector gears.
- Finger flexion/extension (all fingers)
- Finger adduction/abduction (four fingers)
- Thumb opposition
- Neutral (rest)
| Input | Single body-powered cable |
| Differentials | Two whiffletrees |
| Hand mass | 331 g |
| Hardware cost | $138 (excluding filament and silicone) |
| Materials | PLA, PETG, cast silicone (Smooth-On Dragonskin 20) |
Gear-Based Clutch Mechanism/: clutch CAD. The full assembly is inShifting Gearbox V12.step.Underactuated Prosthetic Hand/: hand CAD.
CAD was created in SolidWorks 2024. STEP files are provided for other CAD tools.
Custom parts are FDM-printed in PLA or PETG, and fingerpads are cast in silicone using printed molds. All other parts (shafts, pins, fasteners, needle roller bearings) are off-the-shelf.
@inproceedings{kontoudis2026bodypowered,
title = {Open-Source Body-Powered Prosthesis with a Selective Gear-Based Clutch Mechanism for Switching Grasp Types},
author = {Pacic, Evan and Jones, Remi and Paiz, Elijah and Kontoudis, George P. },
booktitle = {IEEE-RAS International Conference on Humanoid Robots (Humanoids)},
year = {2026}
}