Force-Sensing Touch Sensor with Segmented Substrate
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing touch sensor systems struggle to accurately detect force inputs and provide effective haptic feedback, often due to limitations in sensor design and integration with human-computer interface systems.
Innovation Solution
The system incorporates a substrate with a first electrode and a cover layer, coupled with a spacer element that allows elastic deformation, and a second electrode opposite the first, along with a controller that detects touch inputs and interprets force magnitudes based on electrical values from the electrodes.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Stability of the object's composition
If a rigid substrate is used to maintain structural stability, then stability is improved, but the ability to detect force inputs through elastic deformation is worsened
Solution Approach 1:
The substrate is divided into rigid and flexible portions, with the rigid portion providing structural stability and the flexible portion enabling elastic deformation for force detection. This segmentation allows the system to simultaneously achieve both stability and measurement precision.
Solution Approach 2:
Different regions of the substrate are assigned different mechanical properties - the first portion is made rigid for stability while the second portion is made flexible for force sensing. This local differentiation of material properties resolves the contradiction between overall stability and local deformability needed for detection.
2Measurement precision
If the distance between electrodes is reduced to increase capacitance sensitivity, then measurement precision is improved, but the risk of electrical breakdown and reliability is worsened
Solution Approach 1:
A dielectric layer is introduced between the first and second electrodes to prevent direct electrical contact while allowing capacitive coupling. This intermediary layer enables the electrodes to be positioned closer together for improved capacitance sensitivity without risking electrical breakdown, thus resolving the contradiction between measurement precision and reliability.
3Measurement precision
If complex sensor integration is implemented to improve force detection accuracy, then measurement precision is improved, but device complexity is worsened
Solution Approach 1:
The force sensing capability is merged with the existing touchscreen substrate structure by incorporating flexible portions and electrode pairs directly into the substrate. This integration approach improves force detection accuracy without significantly increasing device complexity, as the sensing elements are combined with rather than added to the existing structure.
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 enables precise detection of force inputs and provides effective haptic feedback by accurately measuring changes in capacitance values, which correspond to changes in distance between the electrodes, thereby enhancing the human-computer interface experience.
Implementation Method 1
The substrate includes a first portion configured to remain substantially rigid and a second portion configured to elastically deform in response to forces applied to the touch sensor surface
Implementation Method 2
the controller is configured to detect a first touch input at a first location on the touch sensor surface, detect a first force magnitude of the first touch input based on a set of electrical values
Data Source
AI summary
One variation of a system for a touch sensor includes: a substrate; a cover layer; a spacer element; a second electrode; and a controller. The substrate includes: a support location arranged on the substrate; and a first electrode arranged proximal the support location. The cover layer defines a touch sensor surface arranged over the substrate. The spacer element: is coupled to the substrate at the support location; and yields to displacement of the substrate downward responsive to forces applied to the touch sensor surface. The second electrode: is arranged opposite the first electrode to define a nominal gap; and is configured to effect electrical values of the first electrode responsive to displacement of the substrate. The controller is configured to: read a set of electrical values from the first sense electrode; and interpret a first force magnitude of a first touch input based on the set of electrical values.