Resistive-Coated Touch Fabric for Full-Surface Sensing
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing touch fabric sensors have 'dead areas' where no touch events are detected due to the use of discrete conducting yarns or printed ribbons, limiting the effective sensing area, especially in woven fabrics where straight yarns restrict the use of larger sensing patterns.
Innovation Solution
A capacitive touch fabric sensor is created by applying a highly resistive material coating over a fabric layer with superimposed electrodes, allowing the entire fabric surface to be used for sensing, even with a limited number of discrete electrodes, by distributing sensitivity across the entire area through a controlled resistive coating.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of manufacture
If discrete conducting yarns or printed ribbons are used as sensing elements, then the structure is simple and easy to manufacture, but the effective sensing area is reduced due to dead regions between sensing elements
Solution Approach 1:
The patent merges the functions of discrete sensing elements by introducing a continuous resistive coating layer that electrically connects all electrodes across the fabric surface. This coating transforms isolated sensing points into a unified continuous sensing field, eliminating dead regions while maintaining the simplicity of discrete electrode placement.
Solution Approach 2:
The resistive coating acts as an intermediary element between discrete electrodes and the touch surface. It distributes and transfers capacitive signals from any point on the fabric to the nearest electrodes, enabling the entire surface to contribute to sensing while keeping the electrode structure simple and manufacturable.
2Ease of manufacture
If straight conducting yarns are used in woven fabric, then the weaving process is simple, but the sensing pattern is restricted to straight lines only
Solution Approach 1:
The patent adds a new dimension to the sensing capability by applying a continuous resistive coating layer over the woven fabric surface. This coating creates a two-dimensional continuous sensing field that transcends the one-dimensional straight yarn constraints, enabling detection of touch events anywhere on the fabric surface while maintaining simple straight yarn weaving.
3Device complexity
If a limited number of discrete electrodes are used, then the device complexity is reduced, but the position sensitivity precision is limited
Solution Approach 1:
The resistive coating serves as a signal distribution intermediary that extends the effective sensing range of each electrode. It conducts capacitive signals from touch events occurring between electrodes to the nearest electrodes, enabling precise position detection with fewer electrodes by effectively distributing sensitivity across the entire fabric surface.
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 configuration effectively utilizes the entire fabric surface for signal pickup, enhancing precision in position sensitivity and avoiding dead areas, allowing for higher precision in detecting touch events across the fabric.
Implementation Method 1
a layer of a highly resistive material coating, the resistive coating layer coating the fabric layer... the plurality of electrodes being electrically coupled with the first layer of resistive material coating
Implementation Method 2
the electronic control unit being configured to evaluate the capacitance variation of the resistive layer that is indicative of a touch event
Implementation Method 3
detecting distortions in an electrostatic field applied to the array that are measurable as changes in capacitance
Data Source
AI summary
It is disclosed a capacity touch fabric sensor (10) comprising a fabric layer (30) and layer (20) of a highly resistive material coating, the resistive coating layer (20) coating the fabric layer (30), wherein the fabric sensor (10) further comprises a plurality of electrodes (40) superimposed to the fabric layer (30), the plurality of electrodes (40) being electrically coupled with the first layer (20) of resistive material coating, each electrode (40) being connected by means of an electrical connection (50) to an electronic control unit (450), the electronic control unit (450) being configured to evaluate the capacitance variation of the resistive layer that is indicative of a touch event on the capacity touch fabric sensor (10).