Woven Sensor Sheet Openings for Stable Resistance Under Tension
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
The reliability of detection accuracy in sensor sheets attached to steering wheels is compromised due to changes in electrical resistance caused by tensile stress, leading to issues with conductive paths and electrode sheets.
Innovation Solution
A sensor sheet design featuring an insulating sheet with conductive electrode sheets and bonding parts, where the electrode sheets are woven with multiple filament assemblies and plated, allowing for deformable openings that maintain electrical connectivity under tension, preventing yield points and reducing stress concentration.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of operation
If the sensor sheet is wrapped around a steering wheel while being stretched and pulled, then the sensor sheet can be attached to the steering wheel, but the conductive path of the first electrode sheet changes due to tensile stress and the electrical resistance value changes
Solution Approach 1:
The patent changes the material parameters of the electrode sheet by using a woven structure with specific filament arrangements and plating treatments. This allows the electrode sheet to maintain its electrical resistance characteristics even when subjected to tensile stress during attachment to the steering wheel, thereby resolving the contradiction between attachability and detection accuracy.
Solution Approach 2:
The patent employs a composite structure combining woven filaments with metal plating layers to create an electrode sheet that possesses both mechanical flexibility for attachment and electrical stability for accurate detection. The composite nature of the material allows it to accommodate deformation while maintaining conductive properties.
2Reliability
If the electrode sheet is made conductive through plating, then electrical conductivity is achieved, but the plating layer may break under tensile stress causing resistance changes
Solution Approach 1:
The patent uses a flexible woven fabric base with applied plating layers that can deform elastically under tensile stress without breaking. The woven structure acts as a flexible substrate that accommodates stretching while the plating layer maintains continuous conductive paths, preventing resistance changes even when the sensor sheet is wrapped around the steering wheel.
3Ease of manufacture
If the sensor sheet structure is simplified, then manufacturing becomes easier, but the ability to maintain electrical connectivity under tension is reduced
Solution Approach 1:
The patent applies plating layers to the woven fabric structure in advance during the manufacturing process, creating a pre-formed conductive electrode sheet. This preliminary action ensures that the conductive properties are built into the structure before attachment, allowing the sensor sheet to maintain electrical connectivity under tension without requiring complex additional components or assembly steps.
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 design suppresses changes in electrical resistance and maintains electrical connectivity even under tensile strain, improving detection accuracy and workability by preventing breakage and stress concentration.
Implementation Method 1
The multiple filament assemblies include multiple filaments and a plating layer formed on at least a part of a surface of the filament. The first electrode sheet and the second electrode sheet are conductive cloths woven with the multiple filament assemblies.
Implementation Method 2
The first electrode sheet includes the first openings that are opened between the multiple filament assemblies. The second electrode sheet includes the second openings that are opened between the multiple filament assemblies. The sensor sheet is configured not to have a yield point showing a local maximum value in a range with a strain being 0.5 to 10% in a stress-strain curve in a tensile test.
Data Source
AI summary
A sensor sheet includes: an insulating sheet; a conductive first electrode sheet disposed on a first surface side of the insulating sheet and having first openings penetrating through; a first bonding part bonding the insulating sheet and the first electrode sheet; a conductive second electrode sheet disposed on a second surface side of the insulating sheet and having second openings penetrating through; and a second bonding part bonding the insulating sheet and the second electrode sheet. The sensor sheet is configured not to have a yield point showing a local maximum value in a range with a strain being 0.5 to 10% in a stress-strain curve in a tensile test. An opening ratio of the first openings in the first electrode sheet is 1% or more and 50% or less. An opening ratio of the second openings in the second electrode sheet is 1% or more and 50% or less.