Amorphous Metallic Microwire Paint for Electromagnetic Absorption

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Solution Overview

Problem

Existing electromagnetic radiation absorbers often require high mass fractions and are not suitable for thin layer structures, failing to effectively attenuate reflectivity across a wide frequency range while avoiding reflection.

Innovation Solution

A process integrating amorphous metallic microwires into a paint with controlled dielectric constants and microwire dimensions, applied in multiple coats to achieve specific attenuation frequencies, using a solvent in limited amounts and mixing at controlled speeds to prevent microwire breakage, allowing for thin layer absorption without excessive mass.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If high mass fraction of conductive particles is used to achieve electromagnetic radiation shielding, then shielding effectiveness is improved, but layer thickness and mass increase making it unsuitable for thin layer structures

Engineering Contradiction:
Improveshielding effectivenessVSAvoidlayer mass
Core Design Contradiction:
ReliabilityVSWeight of stationary object

Solution Approach 1:

The patent changes the physical parameters of the conductive elements by using amorphous metallic microwires with specific length (0.1-20mm) and diameter (3-15 microns) ratios, along with controlled dielectric constant (2-1000) and solvent content (0-20%), to achieve effective electromagnetic radiation attenuation in thin layers without requiring high mass fractions

Inventive Principle:
Principle #35Parameter changes

Solution Approach 2:

The patent creates a composite paint material combining amorphous metallic micrawires with a dielectric matrix, where the specific composition ratio and properties of each component work together to achieve both thin layer applicability and effective electromagnetic radiation absorption

Inventive Principle:
Principle #40Composite materials

2Ease of manufacture

If conventional paint mixing methods are used to integrate metallic micrawires, then mixing simplicity is improved, but micrawire breakage increases reducing absorption effectiveness

Engineering Contradiction:
Improvemixing simplicityVSAvoidmicrawire integrity
Core Design Contradiction:
Ease of manufactureVSStrength

Solution Approach 1:

The patent specifies controlled mixing parameters including maximum speed depending on micrawire length and beating time limits to prevent micrawire breakage while achieving adequate dispersion in the paint matrix

Inventive Principle:
Principle #35Parameter changes

Solution Approach 2:

The patent uses a dielectric matrix as an intermediary medium that protects the amorphous metallic micrawires during the mixing and application process, reducing direct mechanical stress and breakage while maintaining dispersion

Inventive Principle:
Principle #24Intermediary (Mediator)

3Ease of operation

If paint is applied without controlled dielectric constant and solvent content, then application simplicity is improved, but attenuation frequency precision deteriorates

Engineering Contradiction:
Improveapplication simplicityVSAvoidattenuation frequency control
Core Design Contradiction:
Ease of operationVSManufacturing precision

Solution Approach 1:

The patent establishes specific parameter ranges for dielectric constant (2-1000) and solvent content (0-20%) that can be adjusted to control the maximum attenuation frequency while maintaining ease of application through standard painting processes

Inventive Principle:
Principle #35Parameter changes

4Reliability

If metallic micrawires are oriented perpendicular to the surface, then absorption effectiveness is improved, but surface uniformity deteriorates

Engineering Contradiction:
Improveabsorption effectivenessVSAvoidsurface uniformity
Core Design Contradiction:
ReliabilityVSShape

Solution Approach 1:

The patent removes (sands) the micrawires that have oriented perpendicular to the surface after the paint has dried, eliminating the surface uniformity problem while retaining the beneficial perpendicular orientation effect on absorption for the micrawires that remain properly embedded

Inventive Principle:
Principle #2Taking out (Extraction)

Solution Approach 2:

The patent discards the improperly oriented micrawires through sanding, removing only the excess perpendicular micrawires that cause surface non-uniformity while preserving the functional micrawire network within the paint layer

Inventive Principle:
Principle #34Discarding and recovering

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 achieves significant attenuation of electromagnetic radiation reflectivity across a wide frequency range, with specific examples showing attenuation levels of 18 dB at 5.3 GHz and -18 dB at 9 GHz, demonstrating effective absorption without excessive mass or reflection.

Implementation Method 1

amorphous magnetic microwires with high magnetic anisotropy having magnetic resonance properties are randomly distributed

Methodology Applied
Scientific EffectMagnetic resonance: Electron Paramagnetic Resonance

Implementation Method 2

paint with metallic micrawires for attenuating the reflectivity of electromagnetic radiation

Methodology Applied
Scientific EffectElectromagnetic radiation absorption: Absorption (EM radiation)

Implementation Method 3

The maximum attenuation frequency of the reflectivity of electromagnetic radiation having a range which is determined by the length l and the diameter dc of the metallic core of the amorphous metallic micrawires, by the proportion of amorphous metallic micrawires in the paint, and by the dielectric constant of the paint

Methodology Applied
Scientific EffectElectromagnetic resonance tuning: Resonance

Data Source

PatentEP2367234B1Paint with metallic microwires, process for integrating metallic microwires in paint and process for applying said paint on metallic surfaces
Publication Date: 2015.09.16 MICROMAG 2000
  • EP2367234B1 patent drawingFigure 1~2
  • EP2367234B1 patent drawingFigure 3~4

AI summary

The present invention relates to a paint with metallic microwires, to the process for integrating metallic microwires to obtain such paint, and to a process for applying said paint on metallic surfaces (1). The process for applying paint is performed in several steps: - applying a first coat (2) of primer on the metallic surface; - applying on the first coat (2) a second coat (3, 3') of paint; - applying on said second coat (3) an active third coat (4) of a paint containing microwires; and - sanding said active third coat (4) with fine grain sandpaper to remove the microwires oriented perpendicular to the plane of the metallic surface; the maximum attenuation frequency of the reflectivity of said electromagnetic radiation being determined within of the range of maximum attenuation frequencies given by the composition of the paint with microwires, and by the thicknesses and dielectric constants of the different coats.