Flexible Graphene Gas Sensor with Metal Nanoparticle Decoration

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Solution Overview

Problem

Existing gas sensors, particularly metal oxide and graphene-based sensors, face limitations in flexibility, transparency, sensitivity, and selectivity for specific gases, especially in wearable and Internet of Things applications.

Innovation Solution

A self-heating flexible graphene gas sensor with micro- or nano-patterning and surface decoration using metal nanoparticles on a transparent flexible substrate, allowing for improved gas-sensing reactivity and selectivity without an external heater, achieved through specific patterning and decoration techniques.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If metal oxide gas sensor is used, then gas detection function is achieved, but flexibility and transparency are lost

Engineering Contradiction:

Improvegas detection functionVSAvoidflexibility and transparency

Core Design Contradiction:

ReliabilityVSAdaptability or versatility

Solution Approach 1:

The patent uses thin film graphene layers (0.2 nm thickness) deposited on flexible substrates to create a gas sensor that maintains both the gas detection function and the flexibility/transparency required for wearable applications. The thin film structure eliminates the rigidity and opacity of conventional metal oxide sensors.

Inventive Principle:

Principle #30Flexible shells and thin films

Solution Approach 2:

The patent creates a composite structure by combining graphene with metal nanoparticles (Au, Pt, Ag, etc.) to form a hybrid material system. This composite approach enhances the gas sensing performance while maintaining the flexible and transparent characteristics of the underlying graphene-film structure.

Inventive Principle:

Principle #40Composite materials

2Adaptability or versatility

If graphene-based gas sensor is used, then flexibility and transparency are achieved, but sensitivity and selectivity are insufficient

Engineering Contradiction:

Improveflexibility and transparencyVSAvoidsensitivity and selectivity

Core Design Contradiction:

Adaptability or versatilityVSMeasurement precision

Solution Approach 1:

The patent applies local quality enhancement by selectively depositing metal nanoparticles on specific regions of the graphene structure. The nanoparticles are positioned at locations where they can maximize their catalytic effect on target gases, thereby locally enhancing the sensing performance without compromising the overall flexibility and transparency of the sensor.

Inventive Principle:

Principle #3Local quality

Solution Approach 2:

The patent changes the physical and chemical parameters of the graphene surface by introducing metal nanoparticles with specific properties (different metals for different gas targets). This parameter modification enables the sensor to achieve high sensitivity and selectivity for specific gases while maintaining the base flexibility and transparency of the graphene substrate.

Inventive Principle:

Principle #35Parameter changes

3Measurement precision

If external heater is used in gas sensor, then gas detection sensitivity is improved, but device complexity and energy consumption increase

Engineering Contradiction:

Improvegas detection sensitivityVSAvoidheater structure

Core Design Contradiction:

Measurement precisionVSDevice complexity

Solution Approach 1:

The patent implements self-service heating by utilizing the electrical resistance of the graphene-metalsilane composite structure itself as the heating element. When voltage is applied, the composite material generates heat through Joule heating, eliminating the need for separate external heater components and reducing device complexity while maintaining gas detection sensitivity.

Inventive Principle:

Principle #25Self-service

Solution Approach 2:

The patent merges the sensing function and heating function into a single integrated structure. The graphene-metalsilane composite serves dual purposes: as the gas sensing active layer and as the self-heating element, thereby simplifying the overall device architecture and reducing the number of required components.

Inventive Principle:

Principle #5Merging (Combining)

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 enhances the sensitivity and selectivity of gas sensors, enabling their use in flexible, transparent, and cost-effective forms suitable for wearable devices and Internet of Things applications, with improved performance in detecting various gases.

Implementation Method 1

Graphene, which has a thickness of 0.2 nm, has high physical and chemical stability, conducts electricity 100 times or higher than copper, and exhibits electron mobility 100 times or faster than silicon

Methodology Applied

Scientific EffectElectron transport: Conduction (electrical)

Implementation Method 2

a part of the pattern of graphene decorated with metal nanoparticles, and detects a gas by applying an external voltage

Methodology Applied

Scientific EffectCatalysis: Catalysis

Implementation Method 3

detects a gas by applying an external voltage

Methodology Applied

Scientific EffectElectrical conduction: Conduction (electrical)

Data Source

PatentUS11585796B2Flexible graphene gas sensor, sensor array and manufacturing method thereof

Publication Date: 2023.02.21 SEOUL NATIONAL UNIVERSITY R&DB FOUNDATION

AI summary

The present invention relates to a surface-decorated flexible graphene self-heating gas sensor, which has a pattern of graphene formed on a flexible substrate, has a part of the pattern of graphene decorated with metal nanoparticles, and detects a gas by applying an external voltage.