All-Terrain Prosthetic Ankle-Foot

Project Overview

This project focused on designing and validating a fully mechanical, dual-axis ankle-foot prosthesis to improve stability and adaptability during walking on uneven terrain. The system provides natural ankle motion without electronics, prioritizing reliability, manufacturability, and cost-effectiveness.

The design centers on passive mechanical compliance to accommodate real-world terrain variations while maintaining structural integrity under repeated physiological loading. All components were developed with rapid prototyping and scalability in mind.

Engineering Objectives

Enable controlled dorsiflexion and plantarflexion during gait
Accommodate inversion and eversion caused by uneven terrain
Ensure structural safety under cyclic body-weight loading
Design for ease of manufacturing and assembly

My Technical Contributions

Developed parametric CAD models and full mechanical assemblies in Siemens NX
Defined load paths, joint interfaces, and component constraints
Selected materials based on strength, stiffness, and manufacturability
Prepared engineering documentation and design rationale

Key Design Decisions

Dual-degree-of-freedom architecture for realistic ankle motion
Spring-based restoring mechanisms to maintain neutral alignment
Modular design enabling rapid iteration and testing

Engineering Analysis & Validation

Finite Element Analysis (FEA) was conducted to assess the structural performance of critical load-bearing components under representative walking loads.

Analysis Setup

Applied vertical and angled loads simulating stance-phase loading
Boundary conditions defined at pylon and ground-contact interfaces
Material models for PETG and rigid photopolymer resin

Results

Critical components showed stress levels within safe material limits
Identified high-stress regions and refined geometry to reduce stress concentrations
Confirmed design validity prior to physical prototyping

Prototyping & Testing

Physical prototypes were produced using FDM 3D printing in PETG and rigid photopolymer resin, enabling rapid validation of fit, function, and mechanical behavior.

Prototype Activities

Assembled and evaluated full prototype for joint range of motion
Tested spring-return mechanisms for consistency and alignment
Compared prototype behavior against CAD simulation predictions
Iterated on component geometry based on physical test observations

All-TerrainProstheticAnkle-Foot