Carbon Nanotube Waveguide Gasket for Broad-Spectrum EMI Shielding

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Solution Overview

Problem

Existing electromagnetic waveguide gaskets lack effective shielding across a broad frequency range, particularly in the MHz to 100GHz spectrum, and require optimization for mechanical properties, shape, and surface chemistry to provide efficient EMI shielding while maintaining cost-effectiveness.

Innovation Solution

A self-supporting body of non-woven carbon nanotubes with integrated apertures, coated with polymers like PVDF, is used as an EMI shielding gasket, allowing for elastic compression and versatile deployment in waveguide applications, enhancing shielding performance and mechanical behavior.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Object-affected harmful factors

If conventional gasket materials (neoprene, copper) are used, then ease of manufacture and cost-effectiveness are maintained, but EMI shielding effectiveness across broad frequency range is insufficient

Engineering Contradiction:
ImproveEMI shielding effectivenessVSAvoidmanufacturing complexity
Core Design Contradiction:
Object-affected harmful factorsVSEase of manufacture

Solution Approach 1:

The patent employs a composite structure combining carbon nanotubes with polymer matrices (epoxy, polyester, polyimide, nylon, or PTFE). This composite approach achieves superior EMI shielding effectiveness across MHz to 100GHz frequencies while maintaining manufacturability through established composite material processing techniques.

Inventive Principle:
Principle #40Composite materials

Solution Approach 2:

The gasket incorporates a porous foam substrate impregnated with carbon nanotubes. The porous structure provides both mechanical compliance for sealing and enhanced EMI shielding through multiple scattering interfaces, achieving broad frequency coverage without compromising ease of manufacture.

Inventive Principle:
Principle #31Porous materials

2Object-affected harmful factors

If carbon nanotube-based EMI shielding gaskets are used, then EMI shielding effectiveness across broad frequency range is improved, but cost of materials increases

Engineering Contradiction:
ImproveEMI shielding effectivenessVSAvoidmaterial cost
Core Design Contradiction:
Object-affected harmful factorsVSQuantity of substance

Solution Approach 1:

The carbon nanotubes are selectively concentrated in regions requiring EMI shielding while using cost-effective polymer matrices in other areas. The foam substrate provides structural support with lower cost materials, while carbon nanotube impregnation is applied specifically for EMI protection zones.

Inventive Principle:
Principle #3Local quality

Solution Approach 2:

The patent optimizes carbon nanotube concentration, foam density, and layer thickness to achieve the minimum effective shielding performance. By adjusting these parameters, the design achieves broad frequency range EMI shielding at reduced material costs compared to solid carbon nanotube structures.

Inventive Principle:
Principle #35Parameter changes

3Object-affected harmful factors

If thick gasket materials are used to improve EMI shielding, then shielding performance improves, but mechanical flexibility and compression elasticity decrease

Engineering Contradiction:
ImproveEMI shielding effectivenessVSAvoidcompression elasticity
Core Design Contradiction:
Object-affected harmful factorsVSEase of operation

Solution Approach 1:

The patent uses a thin foam substrate impregnated with carbon nanotubes rather than thick solid materials. The foam structure provides inherent flexibility and compression elasticity while the carbon nanotube network maintains EMI shielding effectiveness, achieving both mechanical compliance and electromagnetic protection.

Inventive Principle:
Principle #30Flexible shells and thin films

Solution Approach 2:

The patent transitions from traditional thick planar gaskets to a three-dimensional foam structure with carbon nanotube networks. This dimensional change allows thin overall thickness while maintaining shielding performance through volumetric distribution of conductive elements throughout the foam matrix.

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

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 non-woven carbon nanotube gaskets demonstrate superior EMI shielding across a broad frequency range, outperforming conventional materials, with PVDF-coated versions showing unexpected attenuation values and improved mechanical properties, making them a cost-effective and high-performance solution.

Implementation Method 1

a self-supporting body of non-woven carbon nanotubes has electromagnetic interference (EMI) shielding capabilities across an extremely broad band of frequencies (typically MHz up to 100GHz)

Methodology Applied
Scientific EffectElectromagnetic interference shielding: Absorption (EM radiation)

Implementation Method 2

PVDF-coated versions showing unexpected attenuation values and improved mechanical properties

Methodology Applied
Scientific EffectElectromagnetic attenuation: Absorption (EM radiation)

Implementation Method 3

the EMI shielding gasket includes a self-supporting body of non-woven carbon nanotubes adapted to incorporate one or more apertures. Under compression, the EMI shielding gasket seals effectively the joint

Methodology Applied
Scientific EffectElastic compression: Elasticity

Data Source

PatentEP4029082B1Electromagnetic waveguide with an EMI shielding gasket
Publication Date: 2024.07.31 Q FLO LTD
  • EP4029082B1 patent drawingFigure 1~2
  • EP4029082B1 patent drawingFigure 3~4
  • EP4029082B1 patent drawingFigure 5~6

AI summary

The present invention relates to an electromagnetic waveguide comprising an electromagnetic interference shielding gasket which includes a self-supporting body of non-woven carbon nanotubes adapted to incorporate one or more apertures and to the electromagnetic interference shielding gasket per se.