Capacitive Sensor Module With Two-Layer Spatial Touch Detection

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Solution Overview

Problem

Existing capacitive sensors are complex and costly, requiring multiple electrically conductive layers, which limits their spatial resolution and increases production costs, making them unsuitable for detecting both object approach and tactile events efficiently.

Innovation Solution

A sensor module with only two conductive layers, comprising a multiplicity of cover electrodes and a deformable insulating layer, operating in self-capacitive, bilaterally capacitive, and tactile configurations to achieve spatially resolved detection of object approach and tactile events.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If multiple electrically conductive layers are used in capacitive sensors, then shielding and detection capabilities are improved, but device complexity and production costs increase

Engineering Contradiction:
Improveshielding capabilityVSAvoidnumber of conductive layers
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The single conductive layer serves multiple functions: it acts as both the detection electrode and the shielding electrode. By configuring the measuring unit to switch between self-capacitive mode (detection) and mutual capacitive mode (shielding), the sensor achieves the functionality of multiple conductive layers while using only one, thereby reducing device complexity and production costs.

Inventive Principle:
Principle #6Universality (Multi-functionality)

Solution Approach 2:

The sensor dynamically switches between different measurement modes (self-capacitive and mutual capacitive) depending on the detection requirement. This dynamic reconfiguration allows the single conductive layer to perform different functions at different times, effectively replacing the need for multiple static conductive layers.

Inventive Principle:
Principle #15Dynamics

2Measurement precision

If multiple electrically conductive layers are used in capacitive sensors, then detection accuracy is improved, but manufacturing costs increase

Engineering Contradiction:
Improvedetection accuracyVSAvoidproduction cost
Core Design Contradiction:
Measurement precisionVSEase of manufacture

Solution Approach 1:

The single conductive layer is designed to perform both detection and shielding functions, eliminating the need for separate conductive layers. This reduces material costs and simplifies the manufacturing process while maintaining detection accuracy through intelligent measurement mode switching.

Inventive Principle:
Principle #6Universality (Multi-functionality)

Solution Approach 2:

The measuring unit changes operational parameters (switching between self-capacitive and mutual capacitive modes) to achieve different detection objectives. This parameter change allows the single conductive layer to adapt to different measurement requirements without requiring additional physical layers, thereby reducing manufacturing complexity and cost.

Inventive Principle:
Principle #35Parameter changes

3Adaptability or versatility

If a sensor module detects both object approach and tactile events, then functionality is improved, but spatial resolution deteriorates

Engineering Contradiction:
Improvedetection functionalityVSAvoidspatial resolution
Core Design Contradiction:
Adaptability or versatilityVSMeasurement precision

Solution Approach 1:

The sensor dynamically switches between self-capacitive mode for approach detection and mutual capacitive mode for tactile event detection. This dynamic mode switching allows the sensor to optimize its measurement configuration for each specific detection task, maintaining high spatial resolution for both functionality types without compromise.

Inventive Principle:
Principle #15Dynamics

Solution Approach 2:

The detection functionality is segmented into distinct measurement modes (self-capacitive and mutual capacitive), each optimized for specific detection purposes. By separating the detection functions into different operational modes rather than using a single unified structure, the sensor maintains high spatial resolution for both approach and tactile detection.

Inventive Principle:
Principle #1Segmentation

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 enables compact, cost-effective detection and localization of object approaches and tactile events, improving spatial resolution and reducing production costs while maintaining high sensitivity.

Implementation Method 1

a sensor element having a first, second and third layer, the first layer comprising a plurality of electrically conductive cover electrodes, the second layer being deformable and electrically insulating, the third layer having an electrically conductive bottom electrode

Methodology Applied
Scientific EffectCapacitance: Capacitance

Implementation Method 2

the second layer being deformable and electrically insulating

Methodology Applied
Scientific EffectElectrical insulation: Dielectric

Implementation Method 3

the second layer being deformable and electrically insulating

Methodology Applied
Scientific EffectDeformation: Deformation

Implementation Method 4

for capacitively and spatially resolved recording of tactile events between an object and the sensor module

Methodology Applied
Scientific EffectMechanical force transmission: Mechanical Force

Data Source

PatentEP3166228B1Sensor module, sensor system and method for capacitive and spatially resolved detection of approaching and contact, use of the sensor module
Publication Date: 2022.05.11 KARLSRUHER INST FUR TECH
  • EP3166228B1 patent drawingFigure 1a~1b
  • EP3166228B1 patent drawingFigure 2
  • EP3166228B1 patent drawingFigure 3a~3b

AI summary

The present invention relates to a sensor module, a sensor system and a method for capacitive and spatially resolved detection of the approach of objects to the sensor module and for capacitive and spatially resolved recording of tactile events between objects and the sensor module. In addition, the invention relates to the use of the sensor module or the sensor system. The sensor module comprises a sensor element (100) which has a first, second and third layer, the first layer comprising a multiplicity of electrically conductive cover electrodes (13), the second layer (10) being deformable and electrically insulating, the third layer has an electrically conductive bottom electrode (8), the second layer being arranged between the first and third layers, the first and third layers being the only electrically conductive layers of the sensor element (100), and the sensor element (100) being designed is to be operated in three different measurement configurations, namely in a self-capacitive approach configuration, a mutually capacitive approach configuration and a mutually capacitive tactility configuration: