Low-Cost and Tough Pneumatic Artificial Muscle (LT-PAM): Design Files and Documentation

This repository contains the complete open-source design files for the Low-Cost and Tough Pneumatic Artificial Muscle (LT-PAM), a McKibben-type soft actuator designed for research and educational use in musculoskeletal and humanoid robotics.

The repository includes:
- STL files for 3D printing (end plugs and mounting holders)
- CAD source files in Autodesk Inventor format (.ipt)
- Editable bill of materials (CSV) listing every off-the-shelf component with supplier, part number, quantity, and cost
- Assembly demonstration video
- A README documenting each file together with the recommended print and assembly settings

Key features:
- Material cost: ~USD 5 per actuator
- Simple and fast, crimp-based assembly (no adhesive in load-bearing connections)
- Tensile capacity: 600–800 N (rupture); recommended working load ~400 N
- Durability: contraction stroke varied by less than 3% over more than 9000 pressurization cycles, with no rupture or leakage
- Reproducible in-house fabrication with small sample-to-sample variability

This hardware is described in detail in the accompanying HardwareX article. This design was inspired by and builds upon the open McKibben artificial muscle fabrication recipe originally shared by the Ishikawa Group Laboratory. For the original recipe, see: https://ishikawa-lab.sakura.ne.jp/mckibben_eng

All design files are released under the CERN Open Hardware Licence Version 2 – Permissive (CERN-OHL-P-2.0), and documentation is released under Creative Commons Attribution 4.0 International (CC BY 4.0).