Coin RFID Integration via Non-Conductive Insert

Resolve Bottlenecks,
Find Innovative Solutions
Generate Solutions

Solution Overview

Problem

RFID systems face interference from conductive materials due to induced eddy currents, which attenuate the electromagnetic field and hinder data transmission in coins with metallic content, making it difficult to identify and authenticate coins reliably.

Innovation Solution

A coin design featuring a non-conductive plastic insert element with an integrated passive RFID transponder, protected by a conductive shielding layer, is used within a metallic base element, minimizing eddy current interference and ensuring effective data transmission.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Illumination intensity

If a metallic base element is used to maintain the metallic character of the coin, then the visual appearance and material properties are improved, but eddy currents are induced that attenuate the electromagnetic field and hinder RFID data transmission

Engineering Contradiction:
Improvemetallic appearanceVSAvoidRFID data transmission
Core Design Contradiction:
Illumination intensityVSReliability

Solution Approach 1:

A non-conductive plastic insert element is introduced as an intermediary between the metallic base element and the RFID transponder. This insert element prevents direct contact between the metal and the RFID components, eliminating eddy current interference while preserving the metallic appearance of the coin. The plastic material acts as a mediator that allows the electromagnetic field to pass through without inducing harmful currents in the conductive base.

Inventive Principle:
Principle #24Intermediary (Mediator)

2Reliability

If a passive RFID transponder is integrated into the coin for identification, then coin authentication capability is improved, but the transponder is vulnerable to damage during processing and use

Engineering Contradiction:
Improvecoin authenticationVSAvoidRFID transponder protection
Core Design Contradiction:
ReliabilityVSStrength

Solution Approach 1:

The RFID transponder is nested within a protective cavity formed in the plastic insert element. This nested structure provides mechanical protection to the fragile transponder components during coin processing and circulation. The transponder is embedded within the insert element, which itself is embedded within the metallic base element, creating a nested protective hierarchy.

Inventive Principle:
Principle #7Nested doll (Nesting)

3Area of moving object

If the RFID identification device is made small for minimal coin size impact, then the coin dimensions are preserved, but the data transmission capability may be reduced

Engineering Contradiction:
Improvecoin sizeVSAvoiddata transmission
Core Design Contradiction:
Area of moving objectVSReliability

Solution Approach 1:

The plastic insert element is designed with optimized dimensional parameters, with a surface area less than 5% of the base element, to minimize impact on coin size. The insert element's thickness and material properties are carefully selected to balance mechanical protection with electromagnetic field penetration, allowing effective RFID data transmission through the minimal plastic barrier while maintaining coin size constraints.

Inventive Principle:
Principle #35Parameter changes

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 allows for reliable identification and authentication of coins by reducing eddy current interference, protecting the RFID device from damage, and maintaining the metallic character of the coin.

Implementation Method 1

If the antenna arrangement of the RFID transponder is brought into the electromagnetic field of the RFID reader, an inductive signal coupling is created between the RFID reader and the RFID transponder

Methodology Applied
Scientific EffectInductive signal coupling: Electromagnetic Induction

Implementation Method 2

eddy currents are induced in the electrically and/or magnetically conductive material due to the alternating magnetic flux, whereby the electromagnetic field generated by the RFID reader on the surface of the respective object is so strongly attenuated

Methodology Applied
Scientific EffectEddy currents: Eddy Currents

Implementation Method 3

a shielding layer consisting of highly permeable materials such as ferrites or special alloys is provided between the antenna arrangement formed from at least one conductor loop and the metallic object surface and suitably oriented in order to largely eliminate the induced eddy currents

Methodology Applied
Scientific EffectFerromagnetism: Ferromagnetism

Data Source

PatentEP2415000B1Coin with an integrated RFID identification device and corresponding manufacturing method
Publication Date: 2014.09.10 MUNZE OESTERR
  • EP2415000B1 patent drawingFigure 1(a)~2(d)
  • EP2415000B1 patent drawingFigure 3~5

AI summary

The invention relates to a coin comprising a preferably disk-shaped metal base element (2) and at least one flat insert element (4), which is received in the disk-shaped metal base element (2). Advantageously, the flat insert element (4) is made of a non-conductive material, preferably plastic, and at least one RFID identification device (5) is provided in the flat insert element (4).