RFID Tag With Segmented Antennas For Thermal Property Measurement

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Solution Overview

Problem

Current wireless sensing technologies face challenges in accurately measuring thermal properties of materials and objects, particularly in non-aerosol composites, due to limitations in thermal conductivity measurement and the need for precise temperature control.

Innovation Solution

The development of wireless sensing devices with integrated RF technology, featuring thermally isolated regions and excitation components, allows for the measurement of thermal properties by comparing temperature variations between known and unknown thermal areas, enabling accurate determination of thermal conductivity, diffusivity, and heat capacity through differential sensing.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Measurement precision

If multiple antennas and ICs are integrated into a single RFID tag, then measurement precision and reliability of thermal properties are improved, but device complexity increases

Engineering Contradiction:
Improvethermal property measurement accuracyVSAvoidRFID tag structure complexity
Core Design Contradiction:
Measurement precisionVSDevice complexity

Solution Approach 1:

The RFID tag is divided into multiple independent functional circuits, each with its own antenna and IC. The tag includes a first circuit with a first antenna and first IC, and a second circuit with a second antenna and second IC. This segmentation allows each circuit to independently measure thermal properties of different target areas, improving measurement precision while maintaining manageable device complexity through modular design.

Inventive Principle:
Principle #1Segmentation

2Area of stationary object

If multiple antennas are disposed on the substrate, then coverage area and sensing capability are improved, but manufacturing precision requirements increase

Engineering Contradiction:
Improvesubstrate coverage areaVSAvoidantenna placement precision
Core Design Contradiction:
Area of stationary objectVSManufacturing precision

Solution Approach 1:

The patent positions multiple antennas in different spatial dimensions on the substrate. The first and second antennas are disposed at different locations and orientations, allowing them to cover different target areas. This dimensional arrangement enables comprehensive coverage while using standard manufacturing tolerances, as each antenna operates independently in its own spatial zone rather than requiring precise overlapping placement.

Inventive Principle:
Principle #17Another dimension (Dimensionality change)

3Measurement precision

If thermal isolation is implemented between heating elements, then measurement accuracy is improved, but device complexity and manufacturing difficulty increase

Engineering Contradiction:
Improvetemperature measurement accuracyVSAvoidthermal isolation implementation ease
Core Design Contradiction:
Measurement precisionVSEase of manufacture

Solution Approach 1:

The patent introduces thermal isolation structures as intermediary elements between the first and second heating elements. These isolation structures act as mediators that prevent thermal crosstalk between adjacent heating zones while maintaining a simple planar substrate design. The thermal isolation is achieved through standard fabrication techniques by creating thermal barriers or gaps between heating elements, balancing measurement accuracy with manufacturing ease.

Inventive Principle:
Principle #24Intermediary (Mediator)

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 approach enables precise measurement of thermal properties, improving accuracy and reliability in assessing material properties, such as thermal conductivity and hydration levels, by utilizing RF communication and thermal isolation techniques.

Implementation Method 1

first and second heating elements for heating respective first and second target areas and electrically coupled to the respective first and second ICs

Methodology Applied
Scientific EffectJoule heating: Joule Heating

Implementation Method 2

first and second sensing elements thermally coupled to the respective first and second heating elements for sensing a temperature of the corresponding heating element

Methodology Applied
Scientific EffectThermal conduction: Conduction (thermal)

Implementation Method 3

an antenna disposed on the substrate; first and second integrated circuits (ICs) disposed on the substrate, each IC electrically coupled to the antenna

Methodology Applied
Scientific EffectElectromagnetic radiation: Electromagnetic Induction

Data Source

PatentEP3215986B1Tag assembly with multiple antennas, ics, and/or sensing elements
Publication Date: 2019.07.03 3M INNOVATIVE PROPERTIES CO
  • EP3215986B1 patent drawingFigure 1A
  • EP3215986B1 patent drawingFigure 1B
  • EP3215986B1 patent drawingFigure 1C

AI summary

At least some aspects of the present disclosure feature a radio frequency identification (RFID) tag adapted to wirelessly communicate with a remote transceiver. The RFID tag includes a substrate; and first and second circuits disposed on the substrate and comprising respective first and second antennas magnetically coupled to one another. At least some aspects of the present disclosure feature a RFID tag having a plurality of RF circuits, where each RF circuit is electronically coupled to a sensing element.