Reduced Graphene Oxide Thermal Material for Infrared Stealth

Solution Overview

Problem

Conventional graphene-based optical devices for infrared stealth require complex fabrication processes and are costly, limiting their practical applications.

Innovation Solution

A thermal material comprising a film of reduced graphene oxide sandwiched between an electrode and a porous membrane, with an ionic liquid within the membrane's pores, allowing for flexible coating and reversible control of apparent temperature through bias voltage application.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Object-affected harmful factors

If chemical vapor deposition of graphene film on nickel foil is used to achieve infrared stealth, then infrared stealth performance is improved, but device complexity and fabrication cost increase significantly

Engineering Contradiction:

Core Design Contradiction:

Object-affected harmful factorsVSDevice complexity

Solution Approach 1:

The patent uses a porous membrane as the substrate for reduced graphene oxide film, replacing the conventional nickel foil. The porous structure allows ionic liquid to be infused within the pores, enabling electrochemical control of thermal radiation properties while maintaining simplicity in fabrication process

Inventive Principle:

Principle #31Porous materials

Solution Approach 2:

The patent creates a composite structure combining reduced graphene oxide film with ionic liquid within the porous membrane. This composite material achieves infrared stealth functionality through the synergistic effect of reduced graphene oxide's optical properties and ionic liquid's electrochemical characteristics

Inventive Principle:

Principle #40Composite materials

2Object-affected harmful factors

If chemical vapor deposition of graphene film on nickel foil is used to achieve infrared stealth, then infrared stealth performance is improved, but fabrication cost increases significantly

Engineering Contradiction:

Core Design Contradiction:

Object-affected harmful factorsVSEase of manufacture

Solution Approach 1:

The porous membrane substrate is a low-cost, easily manufacturable material that replaces expensive nickel foil. Its porous structure enables simple infusion of ionic liquid, eliminating complex deposition processes and reducing overall fabrication cost

Inventive Principle:

Principle #31Porous materials

Solution Approach 2:

The patent employs reduced graphene oxide deposited on porous membrane as a cost-effective alternative to expensive conventional graphene materials. The simple fabrication process using aqueous suspension and filtration makes the device economically viable

Inventive Principle:

Principle #27Cheap short-living objects (Disposable)

3Ease of manufacture

If reduced graphene oxide film is deposited on porous membrane with ionic liquid infusion, then fabrication simplicity and cost are improved, but infrared stealth control capability must be maintained

Engineering Contradiction:

Core Design Contradiction:

Ease of manufactureVSObject-affected harmful factors

Solution Approach 1:

The porous membrane structure serves dual purposes: it provides a simple substrate for reduced graphene oxide deposition and acts as a reservoir for ionic liquid. The porous structure enables easy infusion of ionic liquid through capillary action or pressure, maintaining fabrication simplicity while enabling thermal radiation control

Inventive Principle:

Principle #31Porous materials

Solution Approach 2:

The ionic liquid acts as an intermediary between the reduced graphene oxide film and the external voltage source. When voltage is applied, ions in the ionic liquid migrate to the reduced graphene oxide surface, modulating its optical properties and enabling dynamic control of infrared radiation

Inventive Principle:

Principle #24Intermediary (Mediator)

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 thermal material effectively suppresses infrared radiation and emissivity, enabling real-time control of thermal radiation and achieving infrared stealth with a low cost and simple fabrication process.

Implementation Method 1

graphene materials, especially graphene oxide, have a strong interaction with light, which enables a significant absorption (2.3% for one atomic layer) across the infrared and visible range

Methodology Applied

Scientific EffectLight absorption: Absorption (EM radiation)

Implementation Method 2

The ionic liquid comprises cations and anions, which may move in opposite directions to either the electrode or the film of reduced graphene oxide when a bias voltage is applied between the electrode and the film of reduced graphene oxide

Methodology Applied

Scientific EffectIon migration: Electrophoresis

Data Source

PatentUS20220322505A1Thermal material and a method of making the same

Publication Date: 2022.10.06

AI summary

There is provided a thermal material comprising an electrode, a film of reduced graphene oxide, a porous membrane that is sandwiched between the electrode and the film of reduced graphene oxide, and an ionic liquid that is disposed within pores of the porous membrane. There is also provided a method of preparing a thermal material. There is further provided a method of changing an article's apparent temperature. There is further provided a device comprising the thermal material as described herein.