Magnetic Sensor Unit for Flexible Material Strain Detection

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Solution Overview

Problem

Existing methods for measuring the strain of flexible material layers, such as electronic strain gauges and optical detection systems, are either costly, complex, or require precise alignment and strong adhesive bonds, which can fail under stress, leading to inaccurate measurements.

Innovation Solution

A sensor unit comprising a measuring magnet and a sensor plate with a measuring device that detects magnetic flux density, attached to the material layer at fixed positions and movable relative to each other, allowing for reliable and cost-effective strain detection by measuring the distance between the magnet and device as the material stretches.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Measurement precision

If electronic strain gauges are used to measure strain, then measurement precision is improved, but device complexity and reliability worsen due to adhesive bonding requirements

Engineering Contradiction:
Improvestrain measurement precisionVSAvoidadhesive bond reliability
Core Design Contradiction:
Measurement precisionVSReliability

Solution Approach 1:

The patent replaces electronic strain gauges that require adhesive bonding with a magnetic field-based measurement system. A magnet is attached to the material surface, and a Hall effect sensor detects changes in magnetic flux density as the material deforms. This substitution eliminates the need for adhesive bonds entirely, using magnetic field interaction instead of mechanical attachment, thereby improving reliability while maintaining measurement precision.

Inventive Principle:
Principle #28Mechanics substitution (Replace mechanical system)

2Measurement precision

If optical detection systems are used for strain measurement, then measurement precision is improved, but device complexity and cost worsen

Engineering Contradiction:
Improvestrain measurement precisionVSAvoidmeasurement system complexity
Core Design Contradiction:
Measurement precisionVSDevice complexity

Solution Approach 1:

The patent replaces complex optical detection systems (such as laser measurement or camera-based image correlation) with a magnetic field-based Hall effect sensor system. The Hall effect sensor detects magnetic flux density changes caused by material deformation, providing accurate strain measurement with significantly reduced system complexity and lower cost compared to optical methods.

Inventive Principle:
Principle #28Mechanics substitution (Replace mechanical system)

3Reliability

If measuring devices are attached to material layers, then measurement reliability is improved, but the material properties are affected

Engineering Contradiction:
Improvestrain measurement reliabilityVSAvoidmaterial property alteration
Core Design Contradiction:
ReliabilityVSObject-affected harmful factors

Solution Approach 1:

The patent uses a magnetic field-based measurement system where a magnet and Hall effect sensor are attached to the material surface. The magnetic field penetrates the material without mechanical stress or chemical interaction, allowing strain measurement while minimizing impact on material properties such as tensile strength, elongation, and flexibility.

Inventive Principle:
Principle #28Mechanics substitution (Replace mechanical system)

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

Enables accurate and reliable strain measurement of flexible material layers without affecting their properties, providing real-time feedback and extending the useful life of the material by detecting strain without damaging adhesives or requiring complex alignment.

Implementation Method 1

a sensor plate, wherein the sensor plate has a measuring device for detecting a parameter representing the magnetic flux density of a magnetic field of the measuring magnet

Methodology Applied
Scientific EffectMagnetic field: Magnetic Field

Implementation Method 2

The measuring device is a Hall sensor that detects a change in a voltage or current value when the magnetic field of the measuring magnet 10 is moved

Methodology Applied
Scientific EffectHall effect: Hall Effect

Data Source

PatentEP4001873B1Sensor unit for flexible material layers
Publication Date: 2025.08.20 3E OEM SPORTS AG
  • EP4001873B1 patent drawingFigure 1
  • EP4001873B1 patent drawingFigure 2A~2B
  • EP4001873B1 patent drawingFigure 3A~3B

AI summary

The present invention relates to a sensor unit for detecting the strain of a flexible material layer. The present invention also relates to a method for detecting the strain of a flexible material layer. To provide a sensor unit and a method for detecting the strain of a flexible material layer, with which the strain of a flexible material layer can be detected cost-effectively and reliably, it is proposed according to the invention that the sensor unit comprises a measuring magnet and a sensor plate, wherein the measuring magnet and the sensor plate are attachable to a material layer, wherein the sensor plate comprises a measuring device for detecting a distance of the measuring magnet, and wherein the measuring device and the measuring magnet are movable relative to each other in a plane of the material layer by the strain of the material layer.