Single Crystal SiC Whisker Composite Microwave Heating

Resolve Bottlenecks,
Find Innovative SolutionsGenerate Solutions

Solution Overview

Problem

Existing materials used for radiant heating, such as silicon carbide, suffer from low heating efficiency, arcing issues, and limited temperature achievement when exposed to electromagnetic radiation, particularly microwave energy, which restricts their application in devices and processes.

Innovation Solution

The development of composite materials incorporating single-crystal silicon carbide whiskers or fibrils that absorb electromagnetic radiation efficiently, achieving high temperatures without arcing, by enhancing the dielectric loss tangent through dopants and favorable morphology, allowing for rapid and effective heating.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Use of energy by moving object

If traditional silicon carbide forms (polycrystalline particulate) are used for microwave heating, then heating capability is achieved, but heating efficiency is low and high concentrations are required

Engineering Contradiction:

Improveheating efficiencyVSAvoidconcentration of silicon carbide

Core Design Contradiction:

Use of energy by moving objectVSQuantity of substance

Solution Approach 1:

The patent changes the crystal structure parameter of silicon carbide from polycrystalline to single crystal, and modifies the morphology from particulate to whisker/fibril form. This parameter change dramatically increases the dielectric loss tangent, improving heating efficiency and reducing the required concentration from high levels to just 0.1-10 wt%

Inventive Principle:

Principle #35Parameter changes

Solution Approach 2:

The patent creates a composite material system combining single crystal silicon carbide whiskers or fibrils with a matrix material. The single crystal silicon carbide provides superior microwave absorption properties while the matrix provides structural support, achieving both high heating efficiency and low concentration requirements

Inventive Principle:

Principle #40Composite materials

2Use of energy by moving object

If metal powder is used to absorb microwave energy, then heating capability is improved, but arcing and sparking occur

Engineering Contradiction:

Improvemicrowave absorptionVSAvoidarcing and sparking

Core Design Contradiction:

Use of energy by moving objectVSObject-generated harmful factors

Solution Approach 1:

The patent changes the material from conductive metal powder to single crystal silicon carbide whiskers/fibrils with specific dielectric properties. This parameter change maintains high microwave absorption capability while eliminating the conductivity that causes arcing and sparking

Inventive Principle:

Principle #35Parameter changes

Solution Approach 2:

The patent replaces expensive metal powders that cause harmful effects with a more practical alternative - single crystal silicon carbide whiskers/fibrils that provide the same heating function without the harmful arcing and sparking effects

Inventive Principle:

Principle #27Cheap short-living objects (Disposable)

3Use of energy by moving object

If polycrystalline silicon carbide is used for heating, then microwave absorption is achieved, but heating rate is slow

Engineering Contradiction:

Improvemicrowave absorptionVSAvoidheating rate

Core Design Contradiction:

Use of energy by moving objectVSProductivity

Solution Approach 1:

The patent changes the crystal structure from polycrystalline to single crystal and the morphology from particulate to whisker/fibril form. This parameter change increases the dielectric loss tangent, transforming the heating rate from slow to rapid

Inventive Principle:

Principle #35Parameter changes

Solution Approach 2:

The patent utilizes the high aspect ratio geometry of whiskers and fibrils (elongated, fiber-like structures) which provides greater surface area and more interaction points with microwave fields compared to spherical or cubic particles, thereby increasing heating rate

Inventive Principle:

Principle #14Spheroidality (Curvature)

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

These composite materials heat quickly and efficiently to high temperatures, overcoming the limitations of traditional silicon carbide forms by achieving higher dielectric loss tangents, reducing the need for high concentrations, and preventing arcing, thus enabling broader applications in heating devices and processes.

Implementation Method 1

composite materials that heat quickly and efficiently to a high temperature by absorption of electromagnetic radiation

Methodology Applied

Scientific EffectElectromagnetic radiation absorption: Absorption (EM radiation)

Implementation Method 2

enhancing the dielectric loss tangent through dopants and favorable morphology, allowing for rapid and effective heating

Methodology Applied

Scientific EffectDielectric heating: Dielectric Heating

Data Source

PatentUS8648284B2Composite materials and devices comprising single crystal silicon carbide heated by electromagnetic radiation

Publication Date: 2014.02.11 GREENLEAF CORP

AI summary

A composite material that increases in temperature upon exposure to electromagnetic radiation includes single crystal silicon carbide whiskers and fibrils in a matrix material. Also disclosed are heat-generating objects that include the composite material, and a method of generating heat.