Flexible Touch Sensor Electrode Branches for Curved Surfaces
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Conventional touch sensors face challenges in effectively detecting touches and proximity on non-flat surfaces due to their rigid design, which limits their ability to be integrated into curved or three-dimensional surfaces without compromising sensitivity and optical clarity.
Innovation Solution
A flexible touch sensor design featuring an array of drive and sense electrodes on a substrate, made from materials like polyethylene terephthalate (PET) or indium tin oxide (ITO), which can be formed into three-dimensional shapes by eliminating gaps between electrode branches, creating a continuous touch-sensitive surface while maintaining capacitive coupling for accurate touch detection.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If a rigid touch sensor design is used, then manufacturing precision and structural stability are improved, but adaptability to curved surfaces and optical clarity are worsened
Solution Approach 1:
The patent applies a flexible substrate instead of a rigid one to enable the touch sensor to conform to curved surfaces while maintaining electrode pattern precision. The flexible substrate allows the sensor to be integrated into non-planar devices without compromising manufacturing precision or optical clarity.
Solution Approach 2:
The electrode array is divided into multiple independent electrode branches that can be separately optimized and positioned. This segmentation allows each electrode branch to be precisely controlled while collectively forming a continuous touch-sensitive surface on curved surfaces.
2Ease of manufacture
If gaps are present between electrode branches, then ease of manufacture is improved, but measurement precision and touch sensitivity are worsened
Solution Approach 1:
The patent merges adjacent electrode branches by eliminating gaps between them, creating a continuous touch-sensitive surface. This merging ensures that touches anywhere on the surface are detected with high precision while maintaining ease of manufacture through a unified electrode structure.
Solution Approach 2:
The electrode branches are designed to form a continuous capacitive coupling structure without gaps, ensuring continuous touch sensitivity across the entire surface. This continuity maintains measurement precision while simplifying the manufacturing process compared to assembling separate electrode components.
3Ease of manufacture
If electrode branches are separated, then ease of manufacture is improved, but optical clarity and surface continuity are worsened
Solution Approach 1:
The patent merges electrode branches to eliminate visible gaps and create a continuous surface that maintains optical clarity. This merging ensures that light transmission is not interrupted by electrode separations, preserving the display quality underneath the touch sensor while remaining easy to manufacture.
Solution Approach 2:
The electrode structure is designed with local continuity, where adjacent electrode branches are positioned to form an unbroken capacitive path. This local quality ensures optical clarity in the electrode regions while maintaining ease of manufacture through standardized patterning processes.
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
Enables accurate detection of touches and proximity on curved surfaces by ensuring continuous electrode contact, reducing optical discontinuities and enhancing user interaction on non-planar devices like computer mice, while maintaining sensitivity and optical clarity.
Implementation Method 1
an array of drive and sense electrodes capacitively coupled to each other across a space or dielectric between electrodes may form a capacitive node
Implementation Method 2
In a single-layer configuration for a self-capacitance implementation, an array of vertical and horizontal conductive electrodes may be disposed in a pattern on one side of the substrate. Each of the conductive electrodes in the array may form a capacitive node, and, when an object touches or comes within proximity of the electrode, a change in self-capacitance may occur at that capacitive node
Data Source
AI summary
A touch sensor includes a flexible substrate, a plurality of sense electrodes and a plurality of drive electrodes disposed on the flexible substrate, a plurality of electrode branches, and a central spine. Each of the plurality of sense and drive electrodes includes electrode teeth, and electrode teeth of the sense electrodes are interdigitated with electrode teeth of the drive electrodes. Each particular electrode branch includes a portion of at least one of the drive electrodes and a portion of at least one of the sense electrodes. The central spine includes tracks that are coupled to the sense and drive electrodes. When the touch sensor is not formed into a three-dimensional shape, at least a portion of one of the electrode branches is separated from an adjacent electrode branch by a gap. When the touch sensor is formed into a three-dimensional shape, the gap is substantially eliminated, thereby forming a substantially continuous touch-sensitive surface.