Stretchable Capacitive Sensing Substrate With Printed Shielding
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Current capacitive sensing technologies in vehicles face interference from metal components like steering wheels and seat frames, leading to distorted signals and installation challenges due to bulky or inflexible shielding systems.
Innovation Solution
A flexible substrate with conductive traces on both sides, made of non-conductive materials like nylon fabric or plastic films, that can stretch and maintain electrical continuity, allowing for thin, multi-functional sensor and shielding layers that can be molded to fit various vehicle components.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Object-affected harmful factors
If traditional layered shielding assemblies are used, then electrical interference is blocked, but the system becomes too thick and bulky for vehicle installation
Solution Approach 1:
The patent combines the sensor mat and shield mat into a single integrated substrate with conductive traces on both faces, eliminating the need for separate layered assemblies. This merging reduces overall thickness while maintaining both sensing and shielding functions simultaneously.
Solution Approach 2:
The patent uses a flexible substrate with thin conductive trace layers on both faces, replacing bulky rigid shielding materials. The flexible nature allows the shielding to be conformally mounted in tight vehicle spaces without requiring thick clearances.
2Object-affected harmful factors
If traditional rigid shielding materials are used, then electrical shielding is effective, but the system cannot be molded to fit diverse vehicle component shapes
Solution Approach 1:
The patent employs flexible substrates with printed conductive traces that can be conformally mounted to various shapes including steering wheels and seat frames. The flexibility allows the shielding to adapt to curved and irregular vehicle component geometries while maintaining electrical continuity.
Solution Approach 2:
The patent uses flexible, stretchable conductive traces that can dynamically adapt to the contours of different vehicle components. The material properties allow the shielding to be stretched and molded during installation to fit diverse shapes while maintaining electrical functionality.
3Volume of moving object
If conductive traces are adhered to flexible substrate, then the system becomes thin and flexible, but maintaining electrical continuity during deformation becomes challenging
Solution Approach 1:
The patent uses flexible substrates with conductive traces that are specifically designed to maintain electrical continuity when stretched or deformed. The conductive trace material and adhesion methods are selected to ensure reliable electrical connections even when the flexible substrate is conformally mounted to curved surfaces.
Data Source
AI summary
An occupant or object sensing system in a vehicle includes electrical circuits for capacitive sensing and corresponding circuits shielding the sensing system from interference. A sensing circuit and a shielding circuit may be printed by screen printing with conductive ink on opposite sides of a non-conductive substrate. The substrate is a plastic film or other fabric that has an elastic memory structure that is resilient to stretching. The conductive inks used to print circuits onto the substrate have a similar resilience to stretching such that the substrate and the circuits thereon can be subject to deforming forces without breaking the printed circuits. The substrate may be covered with a carbon polymer layer to provide alternative conductive paths that enable fast recovery for conduction in the presence of any break in the printed conductive traces on the substrate.