Flexible Touch Sensor Panel with Serpentine Electrode Connectors
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Conventional touch sensor panels lack flexibility, making them unsuitable for integration into wearable devices or surfaces that require mechanical flexibility, such as watch straps, where they need to conform to the user's wrist and withstand stretching and bending without compromising electrical coupling.
Innovation Solution
The development of flexible touch sensor panel architectures where electrode connectors are patterned to allow touch electrodes to move closer or farther apart while maintaining electrical coupling, using serpentine or butterfly routing patterns that can flex and change shape in response to mechanical forces, and can be layered in different layers to avoid interfering with gaps in the electrodes for light transmission.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If conventional rigid touch sensor panels are used, then electrical coupling between electrodes is maintained, but flexibility and ability to conform to curved surfaces are lost
Solution Approach 1:
The electrode connectors are designed with serpentine or butterfly routing patterns that allow dynamic deformation during stretching or bending. These patterns enable the connectors to change shape and absorb mechanical stress while maintaining continuous electrical pathways between electrodes, thus preserving electrical coupling during flexible deformation.
Solution Approach 2:
The touch sensor panel employs flexible substrate materials and thin-film electrode structures that inherently provide mechanical flexibility. The electrode connectors are integrated into this flexible architecture, allowing the entire assembly to bend and conform to curved surfaces while maintaining functional integrity.
2Strength
If electrode connectors are made rigid to maintain electrical coupling, then electrical connectivity is stable, but the panel cannot withstand stretching and bending forces
Solution Approach 1:
The serpentine and butterfly routing patterns are specifically designed to dynamically adapt to mechanical deformation. These patterns incorporate loops, curves, and redundant pathways that allow the connector to stretch and bend without breaking electrical continuity, effectively managing mechanical stress through geometric design rather than material complexity.
Solution Approach 2:
The electrode connectors are divided into multiple segments along their length, with each segment capable of independent deformation. This segmentation allows the connector to distribute mechanical stress across multiple sections, preventing failure at any single point while maintaining overall electrical connectivity during flexing and stretching.
3Illumination intensity
If solid electrodes are used to ensure electrical coupling, then conductivity is high, but light transmission is blocked
Solution Approach 1:
The electrodes are designed with non-uniform local properties, featuring transparent or transparent-conductive material regions where light transmission is needed and more conductive regions for electrical coupling. The electrode connectors use serpentine patterns that route around gap regions, maintaining electrical pathways while allowing light to pass through designated transparent areas without obstruction.
Data Source
AI summary
Flexible touch sensor panels can be implemented on a strap of a wearable device. A flexible touch sensor panel can provide an additional touch sensitive surface for a user to activate functions on the wearable device without covering a touch screen of the wearable device. In some examples, the flexible touch sensor panels can include electrode connectors configured to electrically couple touch electrodes of the flexible touch sensor panel. In some examples, the electrode connectors can have a serpentine routing pattern configured to allow the touch electrodes to move closer together or farther apart while maintaining electrical coupling between the touch electrodes. In some examples, the touch electrodes can have gaps configured to allow light to pass through the gaps. In some examples, an LED panel can be formed below or one or more waveguide layers can be formed above the flexible touch sensor panel.