Coil-Wound Elongation Sensor With EMI Shielding for Repeatable Displacement

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Solution Overview

Problem

Conventional sensor devices using elastic substrates with metal conductors suffer from plastic deformation, leading to reduced precision in elongation measurements, especially under repeated loading conditions, due to the substrate's and conductor's plastic deformability, which affects the axial dimension and measurement repeatability.

Innovation Solution

A sensor device with a core material having a tensile modulus of 1 to 250 GPa, an insulating layer, and an electromagnetic wave shielding layer, utilizing a conductor with low electrical resistance, and a measuring means that detects impedance changes to calculate elongation displacement, ensuring low residual strain and high repeatability.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If a non-contact type sensor is used to avoid contamination from sterilization, then reliability is improved, but measurement precision deteriorates due to foreign substances like condensation and steam interfering with the measurement

Engineering Contradiction:
Improvesterilization resistanceVSAvoidtemperature measurement accuracy
Core Design Contradiction:
ReliabilityVSMeasurement precision

Solution Approach 1:

The sensor system is divided into two separate sensors: a non-contact type sensor for sterilization-resistant temperature measurement and a contact type sensor for accurate temperature measurement. Each sensor handles specific measurement conditions, and their data is integrated to achieve both reliability and precision.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

A temperature distribution map is introduced as an intermediary to correlate measurements from both sensors. The map enables the non-contact sensor's sterilization-resistant measurements to be adjusted and validated against contact sensor data, resolving the precision issue while maintaining reliability.

Inventive Principle:
Principle #24Intermediary (Mediator)

2Measurement precision

If a contact type sensor is used to ensure accurate temperature measurement, then measurement precision is improved, but reliability deteriorates due to contamination and damage from sterilization processes

Engineering Contradiction:
Improvetemperature measurement accuracyVSAvoidsterilization resistance
Core Design Contradiction:
Measurement precisionVSReliability

Solution Approach 1:

The sensor system is divided into two separate sensors: a non-contact type sensor for sterilization-resistant temperature measurement and a contact type sensor for accurate temperature measurement. Each sensor handles specific measurement conditions, and their data is integrated to achieve both reliability and precision.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The contact type sensor is designed to be replaceable and sterilizable. After contamination or damage from sterilization, the sensor can be discarded and replaced with a new one, maintaining measurement precision without compromising overall system reliability.

Inventive Principle:
Principle #34Discarding and recovering

3Measurement precision

If multiple sensors are used to achieve both sterilization resistance and measurement accuracy, then reliability and measurement precision are both improved, but device complexity increases

Engineering Contradiction:
Improvetemperature measurement accuracyVSAvoidsensor system structure
Core Design Contradiction:
Measurement precisionVSDevice complexity

Solution Approach 1:

The temperature distribution map generation unit merges data from both sensors into a unified temperature distribution representation. This integration approach simplifies the overall system by providing a single comprehensive output that leverages the strengths of both sensor types without requiring complex separate processing systems.

Inventive Principle:
Principle #5Merging (Combining)

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 sensor device provides precise and repeatable elongation displacement measurements, maintaining stability even in severe environments, by minimizing plastic deformation and enhancing the core material's resistance to stress and temperature changes.

Implementation Method 1

a light-receiving element having a light-receiving surface that receives light from a specific direction

Methodology Applied
Scientific EffectThermal radiation: Thermal Radiation

Data Source

PatentEP3825646B1Sensor device and sensing method
Publication Date: 2024.10.30 TEIJIN LTD
  • EP3825646B1 patent drawingFigure 1
  • EP3825646B1 patent drawingFigure 2
  • EP3825646B1 patent drawingFigure 3

AI summary

This sensor device includes: a core using a core material for which residual strain after 2% elongation is no more than 0.4%; a conductor that has an electrical resistance value of no more than 1kΩ/m and that is wound around the outer circumferential part of the core in a coil shape; a sensor member that has an electromagnetic wave shielding layer which shields the conductor from external electromagnetic waves; and a measuringmeans for detecting electrical signals from the sensor member and for measuring displacement of the sensor member on the basis of changes in the electrical signals.