OPEN-SOURCE LEG: A BIONIC LEG FOR RESEARCH LABS
A shared open platform for powered prosthetic legs — one common design plus a Python SDK, so labs stop rebuilding a bionic leg from scratch.
by Neurobionics Lab, University of Michigan
RoboticsMedical
- difficulty
- ●●●●●
- time
- a serious project
- license
- LGPL-2.1
- repo
- repo ACTIVE113 stars
●●●●● · a serious project · LGPL-2.1 · 113 stars · repo ACTIVE
WHAT YOU’LL NEED
- 3D printer + filament — printable parts — files are in the repo
- Electronic parts — full list with part numbers in the repo BOM
- Dev board / microcontroller — runs the project firmware
- Soldering kit + basic tools — one-time buy, serves every future build
Partner
COMPAREE VERDICT
The Open-Source Leg is a quietly important project: instead of every lab building a powered prosthetic leg from scratch, the University of Michigan's Neurobionics group created one shared open design plus a clean Python SDK, so researchers can standardize and compare results. It's modular — knee-only, ankle-only, or full knee-ankle — and it's backed by a Nature Biomedical Engineering paper. Two things to understand: the GitHub repo you find is the control library (pip-installable), while the physical hardware (CAD, electronics) lives on opensourceleg.org and uses commercial actuators; and this is a research-grade, load-bearing wearable, not a certified medical device. For a robotics or biomechanics lab, it's an excellent standardized platform; for a hobbyist, it's more study-and-admire than weekend-build.
IN THE REPO
NOT IN THE REPO
- —The GitHub repo is a Python control library / SDK — not the hardware CAD/BOM
- —The physical knee-ankle hardware lives on opensourceleg.org (OnShape CAD, U-M electronics)
- —It targets commercial actuators (Dephy, Moteus, T-Motor) and runs on a Raspberry Pi
- —It's a research-grade load-bearing device, not a certified clinical prosthesis
Can I build this?
Build at your own risk. Projects involve tools, electronics and sometimes mains voltage — follow the creator’s safety notes.
Partner · KickstarterHeyGears G1: 10M+ colors and transparent parts in one print, plus UV printing on flat objects. Figures, parts and labels — no painting.
Videos
Open-source bionic leg aims to rapidly advance prosthetics1:29
Michigan Engineering's overview of the platform.
Gallery
Start here
Navigation into the creator’s own docs — we don’t rewrite the guide, we route you to the source.
- 1.Read the docs (the SDK docs)
- 2.Watch the overview (what it's for)
- 3.See the hardware (CAD, electronics, community)
- 4.Install the SDK (pip install opensourceleg)
- 5.Read the paper (Nature Biomedical Engineering 2020)
Resources
Documentation, files and community threads for this build — we link straight to the original sources and never rehost the creator’s files.
KNOWN ISSUES
- The GitHub repo is the Python SDK — the hardware CAD/BOM/electronics live on opensourceleg.org, not the repo
- It relies on commercial actuators (Dephy, Moteus, T-Motor) — it isn't a from-scratch build
- It's a research-grade load-bearing device, not a certified clinical prosthesis — wearing it needs trained supervision
Is this a prosthesis I can wear?
It's a research platform, not a certified clinical device. Labs use it to study powered prosthetics; wearing it requires trained supervision and a safe rig.
What's actually open?
A shared hardware design (CAD on OnShape via opensourceleg.org) and a clean Python control SDK (pip-installable), so labs can standardize instead of rebuilding from scratch.
Do I need special motors?
Yes — it targets commercial actuators (Dephy ActPack, Moteus, T-Motor) and runs the control on a Raspberry Pi.
What does it cost?
Band $$$ — research-grade with commercial actuators, but cheaper than proprietary powered prostheses. The hardware site has current prices.
Community builds
No community builds yet — be the first, we feature the best ones.
Discussion1
FROM THE COMPAREE TEAM
The pitch is that prosthetics labs stop rebuilding bespoke legs and standardize on one shared design. Does converging on a single platform speed up research, or narrow it?
Neurobionics Lab, University of Michigan
Created a shared open-source powered prosthetic leg and a Python SDK so research labs could standardize on one platform, published in Nature Biomedical Engineering.
Keep building — related projects
Same category, picked by how close they are to this build.
FULL CADDummy-Robot — compact 6-axis desktop robotic arm (15k stars)
RoboticsOpen-hardware●●●●●expert
FULL CADNASA published the plans for its Mars rover so you can build one
RoboticsOpen-hardware●●●●○advanced
Partner · KickstarterCodeeBot: build the robot from Lego-compatible bricks and program it by hand; a GPT tutor explains each step.
FULL CADBuild NASA-JPL's Open-Source Mars Rover
RoboticsSpace●●●●○advanced
FULL CADElectronBot — cute WALL-E-inspired desktop robot (9.4k stars)
RoboticsOpen-hardware●●●●●expert
DISCLAIMER
- Comparee is not the author of the projects featured here. All rights to each project belong to its creator — every page links to the original source, and we never host creators’ files.
- Information is provided without warranty and may become outdated as projects evolve. Prices are indicative bands only — always check the creator’s parts list for current costs.
- Building and operating any project is at your own responsibility. Protective equipment, safe workshop practice and compliance with local regulations are the builder’s responsibility.
CompareeTEAM1mo ago
Clarification we think matters: the GitHub repo is a pip-installable Python SDK, not the leg — the actual knee-ankle hardware lives on the project site as OnShape CAD, and it drives commercial actuators from Dephy, Moteus and T-Motor rather than printed ones. The work behind it was published in Nature Biomedical Engineering. Anyone in a lab that's adopted it — did standardizing actually help?