Steering Wheel Sensor Mat Printing for Integrated EMI Shielding
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Current steering wheel sensor mats face challenges due to signal interference from the metal steering wheel frame, complex manufacturing processes, and limited flexibility in design and materials, leading to increased manufacturing time and material constraints.
Innovation Solution
The development of sensor mats with printed sensing and shielding loops using conductive ink on a versatile base substrate and insulating material, allowing for customizable designs and reduced noise interference through adjustable insulation thickness and flexible ink patterns.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If wire loops are sewn to fabric or foam substrate to create sensor mats, then the sensor mat can detect hand presence, but the manufacturing process becomes time consuming and complex
Solution Approach 1:
The patent replaces the mechanical sewing process with a printing process. Conductive ink is printed directly onto the substrate to form sensing loops, eliminating the need for physical wire stitching. This substitution of printing for sewing dramatically reduces manufacturing complexity and time while maintaining the electrical conductivity and sensing functionality of the loops.
Solution Approach 2:
The patent changes the physical state and form of the conductive element from discrete wire segments (requiring stitching) to a continuous printed conductive ink pattern. This parameter change in the form factor of the conductive path allows for direct printing application, simplifying the manufacturing process and improving production efficiency.
2Object-affected harmful factors
If separate wire stitch layouts are designed for sensor and shield on different mats, then shielding can be provided, but the design process becomes time consuming and complex
Solution Approach 1:
The patent combines the sensing loop design and shielding loop design into a single integrated mat structure. Both the sensing functionality and electromagnetic shielding are implemented within the same substrate using printed conductive ink patterns, eliminating the need for separate mats and reducing overall design complexity while maintaining effective shielding against electrical interference.
Solution Approach 2:
The printed conductive ink patterns serve multiple functions: they create both the sensing loops for hand detection and the shielding loops for electromagnetic interference protection. This multi-functionality is achieved by designing interconnected conductive patterns that simultaneously perform sensing and shielding roles, reducing the number of components and simplifying the overall system design.
3Ease of manufacture
If traditional manufacturing methods are used with available materials, then production can proceed, but the ability to use available space on the base substrate is limited
Solution Approach 1:
The patent changes the form factor of conductive elements from rigid wire to flexible printed ink, allowing the sensing loops to be configured in optimized patterns that fully utilize the available substrate area. The printed conductive ink can be deposited in complex, space-efficient geometries that maximize the use of the base substrate, improving both space utilization and manufacturing feasibility.
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 solution enhances the manufacturing efficiency and flexibility of sensor mats, reduces unwanted electrical interference, and allows for more precise installation, thereby improving the accuracy and reliability of hand detection systems in steering wheels.
Implementation Method 1
sensor mats around a rim of the steering wheel frame that are configured for detecting the presence of a driver's hand using capacitive-type sensing
Implementation Method 2
one or more printed shielding loops adjacent the sensing loops and separated from the sensing loops by a layer of insulating material
Data Source
AI summary
Systems and methods of printing sensor loops on a sensor mat for use in a steering wheel are disclosed herein. For example, the sensor mat may include a base substrate, one or more printed sensing loops, and an insulating material. The printed sensing loops are made with conductive ink that is disposed upon the base substrate or the insulating layer from a print head and adheres thereto. These sensor mats are versatile with respect to the type of base substrate and insulating materials that may be used, the shape of the sensing loops, and the area each loop may occupy. Shielding loop(s) may also be printed adjacent the sensing loop(s). This configuration allows shielding for the sensing loops as part of the sensing mat, which may reduce the thickness of the steering wheel rim and manufacturing and installation times.