Auxetic Dielectric Elastomer Heel Insert for Quadratic Power Generation
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Deployed military personnel carry heavy replacement batteries, and existing energy harvesting technologies from footwear heel strikes are inefficient, often requiring additional effort and leading to discomfort and fatigue.
Innovation Solution
The use of auxetic materials with negative Poisson ratios in dielectric elastomer generators and piezoelectric systems within shoe heel inserts to enhance mechanical-to-electrical conversion efficiency by amplifying areal changes during heel strikes, allowing for increased power generation without additional effort.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Power
If auxetic materials are used in dielectric elastomer generators, then power generation efficiency increases quadratically, but device complexity increases
Solution Approach 1:
The patent changes the Poisson ratio parameter from positive to negative by using auxetic materials, which fundamentally alters the mechanical response to compression. This parameter change enables quadratic improvement in areal strain and power generation efficiency without requiring complex system architecture
Solution Approach 2:
The patent employs composite material structures combining auxetic materials with dielectric elastomers and piezoelectric materials. These composites leverage the negative Poisson ratio of auxetic materials to amplify deformation while maintaining the functional properties of dielectric and piezoelectric layers, achieving enhanced power generation through material composition rather than mechanical complexity
2Use of energy by moving object
If existing energy harvesting technologies are used, then energy can be harvested from heel strikes, but additional effort is required leading to discomfort and fatigue
Solution Approach 1:
The patent enables the shoe heel insert to harvest energy autonomously from normal heel strike motion without requiring additional user effort. The auxetic material's negative Poisson ratio automatically amplifies the areal change during compression, converting mechanical energy to electrical energy through the dielectric elastomer or piezoelectric effect, making the system self-powered and comfortable for continuous wear
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
This approach significantly improves energy harvesting efficiency, enabling a quadratic increase in power per heel strike and reducing the weight of replacement batteries needed, while maintaining comfort and minimizing fatigue.
Implementation Method 1
A dielectric elastomer generator includes a first auxetic conductive electrode layer, a second auxetic conductive electrode layer, and at least one auxetic dielectric associated in layered orientation between the first and second auxetic conductive electrode layers
Implementation Method 2
at least one dielectric elastomer layer associated in layered orientation between the first and second conductive electrode layers
Implementation Method 3
The use of auxetic materials with negative Poisson ratios in dielectric elastomer generators and piezoelectric systems within shoe heel inserts to enhance mechanical-to-electrical conversion efficiency
Data Source
AI summary
An energy harvesting device using auxetic materials includes a first auxetic conductive electrode layer. A second auxetic conductive electrode layer is associated with the first auxetic conductive electrode layer. The auxetic conductive electrode layers have negative Poisson ratios. At least one dielectric elastomer layer is associated in layered orientation between the first and second auxetic conductive electrode layers.