Adaptive-Stiffness Ankle Brace with Strain-Stiffening Metamaterial
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Conventional ankle braces are either too stiff, affecting normal gait and comfort, or too flexible, providing insufficient support during high-intensity activities, leading to discomfort and reduced compliance.
Innovation Solution
Development of adaptive-stiffness ankle braces using metamaterials that emulate the strain-stiffening behavior of ligaments, offering lower stiffness during low-demand activities and increased stiffness during high-demand activities, integrating a flexible sleeve with a metamaterial composed of hexagonal ring-shaped unit cells made of thermoplastic polyurethane.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Strength
If conventional ankle braces use high stiffness materials, then support during high-intensity activities is improved, but comfort during normal activities deteriorates
Solution Approach 1:
The patent applies dynamics by making the brace stiffness variable rather than fixed. The metamaterial structure dynamically adjusts its stiffness based on the applied load: it remains flexible during normal low-intensity activities for comfort, and automatically stiffens during high-intensity activities for support. This resolves the contradiction by allowing the brace to adapt its mechanical properties to different usage conditions.
Solution Approach 2:
The patent changes the stiffness parameter of the brace material based on the applied force. The metamaterial exhibits strain-stiffening behavior where the stiffness parameter increases as the strain increases. This allows the brace to provide appropriate support stiffness only when needed during high-intensity activities while maintaining comfort during normal activities.
2Ease of operation
If conventional ankle braces use low stiffness materials, then comfort during normal activities is improved, but support during high-intensity activities deteriorates
Solution Approach 1:
The brace uses a dynamic stiffness mechanism through metamaterials that automatically adjust their mechanical properties. During normal activities with low applied forces, the material remains compliant and comfortable. When high forces are applied during intense activities, the material dynamically transitions to a stiff state to provide necessary support, thus resolving the contradiction between comfort and support.
Solution Approach 2:
The metamaterial exhibits changing stiffness parameters in response to applied strain. At low strain levels during normal activities, the stiffness parameter is low for comfort. At high strain levels during intense activities, the stiffness parameter increases automatically to provide support, resolving the contradiction between comfort and support requirements.
3Reliability
If ankle braces maintain constant high stiffness, then protection during injuries is improved, but gait naturalness and compliance deteriorate
Solution Approach 1:
The patent applies dynamics by replacing constant stiffness with variable stiffness that adapts to activity level. During normal gait with low forces, the brace remains flexible to maintain natural movement patterns and comfort. During injury-prone high-intensity activities with high forces, the brace automatically stiffens to provide protection, thus resolving the contradiction between protection and gait naturalness.
Solution Approach 2:
The stiffness parameter of the brace material changes dynamically based on applied load. During normal activities, the low stiffness parameter allows natural gait. During high-intensity activities where injury risk increases, the stiffness parameter automatically increases to provide protection, resolving the contradiction between protection and compliance.
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
Enhances comfort during normal activities and support during high-intensity activities, improving wear compliance and reducing the incidence of repetitive injuries by mimicking the mechanical properties of ligaments.
Implementation Method 1
metamaterials that emulate the strain-stiffening behavior of ligaments
Implementation Method 2
thermoplastic polyurethane
Data Source
AI summary
Embodiments of the presently disclosed technology provide orthopedic braces that employ adaptive/variable stiffness metamaterials to emulate the strain-stiffening behavior of ligaments. These orthopedic braces may provide lower rigidity during low-demand/low-strain activities (e.g., normal gait movements) and increased rigidity under high-demand/high-strain activities (e.g., running and other movements that require larger ranges of motion and rotational velocities).