Temperature-Sensing RFID Tag Shielding for Accurate Article Readings

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Solution Overview

Problem

Existing temperature-sensing RFID devices struggle to accurately measure the temperature of an article due to interference from environmental conditions, which can lead to incorrect temperature readings.

Innovation Solution

The implementation of a shielding structure and a thermally conductive or absorbent structure in the RFID device to protect the temperature sensor from environmental factors and enhance thermal coupling with the article.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Ease of operation

If the RFID device is exposed to the environment for easy operation, then the device can be easily attached and read, but the temperature sensor measures environmental temperature instead of article temperature

Engineering Contradiction:
Improveease of attachmentVSAvoidtemperature measurement accuracy
Core Design Contradiction:
Ease of operationVSMeasurement precision

Solution Approach 1:

The RFID device is segmented into distinct functional zones: an environmental interface portion (antenna, housing) that interacts with the external environment, and a protected sensing portion (temperature sensor, RFID chip) that is thermally isolated from the environment. This segmentation allows the device to be easily attached while maintaining measurement accuracy by preventing thermal coupling between the sensor and environmental factors.

Inventive Principle:
Principle #1Segmentation

2Device complexity

If the RFID chip is directly exposed to the environment, then the device structure is simple, but the temperature reading reflects environmental conditions rather than article conditions

Engineering Contradiction:
Improvestructural complexityVSAvoidtemperature measurement accuracy
Core Design Contradiction:
Device complexityVSMeasurement precision

Solution Approach 1:

A non-conductive, non-metallic barrier layer is introduced as an intermediary between the RFID chip and the external environment. This barrier layer is thermally insulating yet allows RF signals to pass through, serving as a mediator that blocks harmful thermal pathways while maintaining electromagnetic communication. This adds minimal structural complexity while significantly improving measurement accuracy.

Inventive Principle:
Principle #24Intermediary (Mediator)

3Measurement precision

If shielding structures are added to protect from environmental factors, then temperature measurement accuracy improves, but device complexity increases

Engineering Contradiction:
Improvetemperature measurement accuracyVSAvoidstructural complexity
Core Design Contradiction:
Measurement precisionVSDevice complexity

Solution Approach 1:

The patent employs thin-film barrier layers and flexible shielding structures that provide thermal protection while maintaining device flexibility and minimizing added complexity. These thin films are integrated into the existing device architecture rather than adding bulky external shields, thus improving measurement accuracy with minimal impact on device complexity.

Inventive Principle:
Principle #30Flexible shells and thin films

Solution Approach 2:

The RFID device utilizes composite material structures combining materials with different thermal and electromagnetic properties. The housing and barrier layers are constructed from composite materials that provide thermal insulation while maintaining RF signal transparency, achieving protection from environmental factors without significantly increasing device complexity.

Inventive Principle:
Principle #40Composite materials

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 improves the accuracy of temperature measurements by isolating the RFID chip from environmental influences and ensuring that the temperature sensed is that of the article rather than the environment.

Implementation Method 1

a shielding structure and a thermally conductive or absorbent structure in the RFID device to protect the temperature sensor from environmental factors

Methodology Applied
Scientific EffectThermal insulation: Thermal Insulation

Implementation Method 2

a shielding structure and a thermally conductive or absorbent structure in the RFID device to protect the temperature sensor from environmental factors and enhance thermal coupling with the article

Methodology Applied
Scientific EffectThermal conduction: Conduction (thermal)

Data Source

PatentEP4266018B1Temperature-sensing RFID device
Publication Date: 2025.01.22 AVERY DENNISON RETAIL INFORMATION SERVICES LLC
  • EP4266018B1 patent drawingFigure 1~3
  • EP4266018B1 patent drawingFigure 4
  • EP4266018B1 patent drawingFigure 5~6

AI summary

A temperature-sensing RFID device includes an RFID chip and an antenna electrically coupled thereto. The RFID chip includes a temperature sensor, while the antenna is adapted to receive energy from an RF field and produce a signal. A shielding structure and/or a thermally conductive or absorbent structure may be associated with the RFID chip. The shielding structure is oriented so as to be positioned between at least a portion of the RFID chip and an outside environment and configured to shield the temperature sensor from at least one environmental factor capable of affecting a temperature sensed by the temperature sensor of an article to which the RFID device is secured. The thermally conductive or absorbent structure is oriented so as to be positioned between at least a portion of the RFID chip and the article and configured to enhance thermal coupling between the temperature sensor and the article.