Variable stiffness apparatuses using an interconnected dual layer fluid-filled cell array
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Conventional seat cushions and ergonomic products using foam or air-filled cell arrays face issues with stiffness changes over time, requiring manual inflation or deflation for variable stiffness, which is inconvenient and inefficient.
Innovation Solution
A dual layer fluid-filled cell array system where interconnected primary and secondary cells allow fluid transfer to adjust stiffness, with geometric and material variations in the secondary cell enabling customizable stiffness and pressure distribution without manual inflation or deflation.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If foam is used as cushioning material, then cost and weight are reduced, but stiffness increases over time leading to increased interface pressure
Solution Approach 1:
The cushioning system uses a fluid-filled cell array where fluid can dynamically redistribute between cells in response to applied loads. This dynamic fluid migration allows the system to adapt its stiffness characteristics over time, preventing the permanent stiffening that occurs with foam materials. The fluid pressure equalization mechanism ensures consistent interface pressure distribution throughout the product lifecycle.
2Stability of the object's composition
If air-filled cell array is used to avoid stiffness change, then interface pressure distribution improves, but manual inflation/deflation is required for variable stiffness
Solution Approach 1:
The fluid-filled cell array system automatically adjusts its stiffness characteristics through passive fluid redistribution between cells. When external loads are applied, fluid naturally migrates from compressed cells to uncompressed cells through interconnected channels, eliminating the need for manual inflation or deflation operations. The system self-regulates pressure distribution based on the applied forces, providing variable stiffness on demand without user intervention.
3Adaptability or versatility
If fluid transfer between cells is enabled, then variable stiffness is achieved automatically, but system complexity increases
Solution Approach 1:
The cushioning system is divided into multiple discrete fluid-filled cells that are interconnected through channels. Each cell can independently respond to localized loads while maintaining fluid communication with neighboring cells. This segmented architecture enables variable stiffness characteristics through simple geometric design of individual cells rather than complex active control mechanisms. The interconnection channels provide passive fluid transfer pathways that emerge from the segmented structure itself.
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
The system provides consistent and customizable interface pressure distribution across surfaces, maintaining minimal stiffness changes over time and eliminating the need for manual adjustments, enhancing user comfort and product longevity.
Implementation Method 1
a second portion defining a second chamber in fluid communication with the first chamber
Implementation Method 2
a flexible first portion having a first end, a second end, and a sidewall extending between the first end and the second end
Data Source
AI summary
Variable stiffness apparatuses using an interconnected dual layer fluid-filled cell array. One example of the present apparatuses comprises: a substrate having a first side and a second side; and a plurality of structures coupled to the substrate, where each structure comprises: a flexible first portion having a first end, a second end, and a sidewall extending between the first end and the second end, the first portion defining a first chamber; and a second portion having a first end, a second end, and a sidewall extending between the first end and the second end, the second portion defining a second chamber in fluid communication with the first chamber; where each of the plurality of structures is coupled to the substrate such that the first portion is disposed on the first side of the substrate, and the second chamber is disposed on the first side or the second side of the substrate.