Zigzag Protruding Electrodes for Accurate Pressure Sensing
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Conventional touch panels with pressure sensing functions face limitations in detecting precise pressure due to the arrangement of pressure sensing devices, which often require larger pressures and are not suitable for display areas, leading to poor user experience and potential damage.
Innovation Solution
A pressure sensing pattern layer with transparent conductive electrodes, each comprising zigzag protruding portions connected to a Wheatstone bridge circuit, allowing for detection of resistance variations and enabling accurate pressure sensing on display areas.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If pressure sensing devices are disposed at non-display areas (e.g., four corners), then the touch panel can detect pressure, but the pressure sensing accuracy is poor and only single point pressure can be detected
Solution Approach 1:
The pressure sensing electrode is divided into multiple protruding portions (first, second, third, and fourth protruding portions) that are distributed at different locations including display and non-display areas. Each protruding portion independently detects pressure, transforming a single-point detection system into a multi-point detection system, thereby improving pressure sensing accuracy without excessive complexity
Solution Approach 2:
The pressure sensing electrode extends from traditional corner-only placement into the display area by adding protruding portions that protrude toward the display region. This spatial dimensionality change allows pressure detection across multiple zones (corner areas and display areas), enabling both multi-point detection and display area applicability
2Measurement precision
If conventional metal line pressure sensing patterns are used, then the structure is simple, but the pattern has small deformation under small pressure making resistance variation hard to detect
Solution Approach 1:
The pressure sensing electrode incorporates protruding portions that create curved and irregular geometries instead of straight metal lines. These protruding structures amplify deformation under pressure, making resistance variations more detectable. The curved paths of the electrode segments increase the effective deformation distance, enhancing sensitivity to small pressure changes
Solution Approach 2:
The electrode structure is designed with specific geometric parameters (protruding portions extending toward display area, controlled line widths of 10-400 μm, and optimized path lengths) that maximize resistance change under pressure. By carefully controlling these parameters, the system achieves high detection sensitivity while maintaining manufacturability
3Adaptability or versatility
If metal pressure sensing patterns are used, then manufacturing is straightforward, but the pattern is not transparent and cannot be applied to display areas
Solution Approach 1:
The electrode material transitions from opaque metal to transparent conductive materials such as ITO (indium tin oxide), silver nanowires, or graphene. This material parameter change enables the pressure sensing electrode to be applied in display areas without blocking light, while the manufacturing process remains compatible with existing thin-film deposition techniques used in display fabrication
Solution Approach 2:
The pressure sensing electrode utilizes transparent conductive composite materials that combine the electrical conductivity of metals with the optical transparency of dielectric materials. Examples include ITO layers, silver nanowire networks embedded in transparent matrices, or graphene structures, achieving both display area compatibility and functional performance
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 solution enhances pressure sensing accuracy and reliability, enabling better user experience by detecting subtle pressure changes and preventing damage, while being applicable to display areas.
Implementation Method 1
Each of the pressure sensing electrodes is electrically connected to a Wheatstone bridge circuit through a first conductive line and a second conductive line. When any of the pressure sensing electrodes is touched, a variation of the resistance of the touched pressure sensing electrode is detected by the Wheatstone bridge circuit.
Implementation Method 2
A resistance of each of the pressure sensing electrodes is an element of the Wheatstone bridge circuit. When any of the pressure sensing electrodes is touched, a variation of the resistance of the touched pressure sensing electrode is detected by the Wheatstone bridge circuit.
Data Source
AI summary
A pressure sensing pattern layer is formed on a substrate and comprises a plurality of pressure sensing electrodes. Each of the pressure sensing electrodes comprises a plurality of protruding portions. The protruding portions are formed from a transparent conductive line which is bent zigzag. Each of the pressure sensing electrodes is electrically connected to a Wheatstone bridge circuit through a first conductive line and a second conductive line. A resistance of each of the pressure sensing electrodes is an element of the Wheatstone bridge circuit. When any of the pressure sensing electrodes is touched, a variation of the resistance of the touched pressure sensing electrode is detected by the Wheatstone bridge circuit.