Piezoelectric Authentication Device Without Electrodes

Resolve Bottlenecks,
Find Innovative SolutionsGenerate Solutions

Solution Overview

Problem

Traditional authentication devices in security documents are vulnerable to failure due to electrode breakage and fail to survive crumpling tests, lacking durability and reliability for flexible substrates like banknotes.

Innovation Solution

An authentication device comprising a piezoelectric material layer generating an electric field in response to mechanical stress, directly attached to an optically responsive layer without a direct electrical connection, ensuring the optically responsive layer changes states based on the electric field, eliminating the need for electrodes and electrical circuits.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If traditional electrodes and electrical circuits are used to conduct charge from piezoelectric material to state changing material, then the authentication device can produce optical state changes, but the device becomes vulnerable to failure when electrodes are cut or broken and cannot survive crumpling tests

Engineering Contradiction:

ImprovedurabilityVSAvoidelectrode structure

Core Design Contradiction:

ReliabilityVSDevice complexity

Solution Approach 1:

The patent removes the vulnerable electrode and electrical circuit components from the authentication device. Instead of using traditional conductive pathways, the invention directly couples the piezoelectric material layer to the state-changing material layer, eliminating the electrodes that are prone to breakage during crumpling tests while maintaining the essential charge conduction function.

Inventive Principle:

Principle #2Taking out (Extraction)

Solution Approach 2:

The patent merges the piezoelectric material layer and the state-changing material layer into a directly coupled structure without intermediate electrodes. This integration eliminates the interface between electrode and active material, creating a more robust configuration that survives mechanical stress while maintaining electrical functionality for optical state changes.

Inventive Principle:

Principle #5Merging (Combining)

2Reliability

If electrodes and electrical circuits are incorporated to enable optical property changes, then the authentication device can function as intended, but the device fails durability testing due to electrode breakage

Engineering Contradiction:

Improvefunctional reliabilityVSAvoidmechanical strength

Core Design Contradiction:

ReliabilityVSStrength

Solution Approach 1:

The patent extracts and removes the electrode components from the device architecture. By eliminating the electrode layer entirely and directly coupling the piezoelectric material to the state-changing material, the invention removes the weak link that causes failure during crumpling tests while preserving the essential electrical conduction pathway needed for optical property changes.

Inventive Principle:

Principle #2Taking out (Extraction)

3Device complexity

If traditional authentication devices with electrodes are used, then optical state changes can be achieved, but the devices require external power sources and activation mechanisms

Engineering Contradiction:

Improvestructural simplicityVSAvoidpower source requirement

Core Design Contradiction:

Device complexityVSUse of energy by moving object

Solution Approach 1:

The patent implements a self-service mechanism where the piezoelectric material layer directly generates and conducts electrical charge to the state-changing material without requiring external power sources or activation devices. The mechanical stress applied to the piezoelectric material self-generates the electric field needed to induce optical state changes, eliminating the need for external electrical connections and power supply infrastructure.

Inventive Principle:

Principle #25Self-service

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 provides a durable and reliable optical security authentication mechanism that can withstand crumpling tests and maintain functionality even if the conductive layers are partially damaged, ensuring the security feature remains operational without reliance on external power or activation devices.

Implementation Method 1

a piezoelectric material layer for generating an electric field in response to mechanical stress

Methodology Applied

Scientific EffectPiezoelectric effect: Piezoelectric Effect

Implementation Method 2

the optically responsive layer being operable between a first state and a second state having different ocular perceptions; wherein the optically responsive layer changes from the first state to the second state in response the electric field generated by the piezoelectric material layer

Methodology Applied

Scientific EffectElectro-optic effect: Electro-Optic Effects

Data Source

PatentUS9082054B2Authentication device for security documents

Publication Date: 2015.07.14 BANK OF CANADA

AI summary

An optical based authentication device that is attachable to a security document having a substrate. The authentication device includes: a piezoelectric material layer for generating an electric field in response to mechanical stress; and an optically responsive layer directly attached to the piezoelectric material layer, the attached layers being absent a direct electrical connection, the optically responsive layer being operable between a first state and a second state having different ocular perceptions. The optically responsive layer changes from the first state to the second state in response the electric field generated by the piezoelectric material layer.