Knitted Textile Pressure Sensor for Uneven Surfaces
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Solution Overview
Problem
Existing textile pressure sensors for capacitive measurement of pressure distribution are not adequately adaptable to uneven surfaces and lack robustness when subjected to loads from objects.
Innovation Solution
A textile pressure sensor utilizing a knitted fabric design for both conductive structures, allowing for increased flexibility and robustness, with conductive areas forming capacitors that can measure pressure distribution on objects of any shape without risk of damage, and incorporating a reversibly compressible dielectric intermediate element.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If a matrix arrangement of mutually insulated strips of conductive foil is used, then capacitive measurement of pressure distribution is enabled, but the sensor is not stretchable and has limited adaptability to uneven surfaces
Solution Approach 1:
The patent replaces rigid conductive foil strips with conductive threads integrated into a knitted fabric structure. The knitted fabric acts as a flexible shell that can stretch and conform to uneven surfaces while maintaining the conductive pathways needed for capacitive measurement. This resolves the contradiction by providing both adaptability to irregular shapes and structural integrity through the interlocked knit pattern.
Solution Approach 2:
The sensor combines conductive threads with non-conductive yarns in a knitted fabric composite. This composite structure allows the sensor to maintain electrical conductivity while gaining the mechanical properties of textile materials, including stretchability and adaptability to uneven surfaces. The composite nature enables simultaneous achievement of electrical functionality and mechanical flexibility.
2Strength
If conventional fabric structures are used for conductive areas, then the sensor can be made flexible, but it lacks robustness when subjected to loads from objects
Solution Approach 1:
The knitted fabric structure serves as a flexible shell that distributes mechanical loads across the entire sensor surface rather than concentrating stress at specific points. The interlocked loops in knitted fabrics provide inherent toughness and resistance to tearing, enabling the sensor to withstand repeated flexing and compression while maintaining flexibility for conforming to body surfaces.
Solution Approach 2:
The knitted fabric structure dynamically adapts its mechanical properties under load. When subjected to compression from objects, the fabric loops deform and redistribute forces, providing robustness. When unloaded, the fabric returns to its original configuration, maintaining flexibility. This dynamic response resolves the contradiction between strength and flexibility.
3Adaptability or versatility
If the sensor is designed to be stretchable for adaptability, then it can conform to body surfaces, but the conductive structures may be damaged under tension
Solution Approach 1:
The knitted fabric acts as a flexible shell structure where the interlocked loops provide inherent tear resistance. When stretched, the loops deform and redistribute tensile forces throughout the fabric structure, preventing localized stress concentration that would lead to tearing. This maintains both stretchability for body conformity and reliability against damage.
Solution Approach 2:
The knitted fabric structure provides beforehand cushioning against tensile damage through its inherent mechanical properties. The loop structure absorbs and distributes tension forces before they can propagate into tears or breaks in the conductive pathways, ensuring reliability even when the sensor is stretched to conform to complex body geometries.
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 knitted fabric design enables the sensor to effectively measure pressure distribution on unevenly shaped objects with enhanced stretchability and tear resistance, making it suitable for various applications, including clothing and complex three-dimensional shapes.
Implementation Method 1
A textile pressure sensor for the capacitive measurement of a pressure distribution on a surface
Implementation Method 2
A dielectric intermediate element (7) is arranged between the first and the second conductive structure, which comprises a fabric, and is reversibly compressible
Data Source
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AI summary
The invention relates to a textile pressure sensor for the capacitive measuring of a pressure distribution of objects of any shape, in particular body parts, on a surface, having a first structure (30a) which is conductive at least in regions and a second structure (30b) which is conductive at least in regions, wherein the first structure and the second structure that are conductive at least in regions are separated from each other by a dielectric intermediate element (48), and wherein conductive regions of the first structure (30a) form capacitors with opposite conductive regions of the second structure (30b). The textile pressure sensor is characterized in that the first and/or the second structure that is conductive at least in regions (30a, 30b) is designed as a knit.