Capacitive Touch Sensor Air-Gap Structure for Accurate Pressure Sensing
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Conventional touch sensors lack effective shielding between electrodes, leading to interference in capacitance signal variations due to external forces or insulator deformation.
Innovation Solution
A touch sensor design featuring two baseplates with a first electrode between them, a pressure sensing module, and an air gap between the second and third electrodes, providing insulation and allowing precise signal measurement through concentrated pressure on the second electrode.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If an insulator is provided between two electrodes to isolate them, then insulation is achieved, but the insulator may be affected by external force or stress, causing deformation that affects capacitance signal variation and reduces measurement precision
Solution Approach 1:
The patent introduces an air gap as an intermediary between the second electrode and third electrode. This air gap serves as the insulating medium instead of a solid insulator, allowing the second electrode to deform under external force without the deformation being transmitted to the third electrode. The air gap maintains electrical isolation while being mechanically compliant, thus resolving the contradiction between insulation effectiveness and measurement precision.
2Reliability
If a solid insulator is used between electrodes, then electrical isolation is provided, but the insulator deforms under external force affecting the other electrode and reducing shielding effect
Solution Approach 1:
The air gap acts as a mediator that provides electrical isolation between the second and third electrodes while being mechanically flexible. When external force is applied, the air gap allows deformation without transmitting mechanical stress to the third electrode, thereby maintaining the shielding effect while ensuring reliable electrical isolation.
3Ease of operation
If external force affects the insulator, then the insulator deforms changing contact areas, but this also affects the other electrode and reduces signal accuracy
Solution Approach 1:
The air gap serves as a mediator that decouples the mechanical deformation from electrical signal transmission. The second electrode can deform under pressure to enable pressure sensing, but the air gap prevents this deformation from affecting the third electrode's electrical field, thus maintaining signal accuracy while enabling ease of operation for pressure sensing.
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 air gap ensures better shielding, enabling accurate measurement of signal changes by isolating the second and third electrodes, thus enhancing the sensor's ability to detect two- and three-dimensional touch inputs accurately.
Implementation Method 1
an air gap is provided between the second electrode and the third electrode
Implementation Method 2
when one of the two baseplates close to the second electrode is touched, the air gap changes a spacing thereof to change a self-capacitance signal of the two signal output sources
Data Source
AI summary
A touch sensor comprises two baseplates arranged at intervals, a first electrode disposed between the baseplates, and a pressure sensing module. Two-dimensional touch control of the sensor is achieved by the first electrode. An insulating material is provided between the module and the first electrode. The module comprises a second electrode based on the insulating material and disposed on a side of the insulating material away from the first electrode, and a third electrode disposed above the other one of the baseplates. The second electrode is not in contact with the third electrode, an air gap is provided between the second and third electrodes, the second and third electrodes are respectively connected to a signal output source. When one of the baseplates close to the second electrode is touched, the air gap changes a spacing to change a self-capacitance signal of the signal output sources.