Polymer Aerogel Sensor for Fast Colorimetric Detection

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Solution Overview

Problem

Current colorimetric sensors suffer from slow response times and limited detection of trace amounts of contaminants due to dense polymer binders that act as diffusion barriers, obscuring color changes and requiring expensive equipment for detection, especially for toxic gases like ammonia and chemical warfare agents.

Innovation Solution

The use of polymer aerogels with high surface areas and controlled pore sizes as binders allows for better penetration and interaction of target molecules with sensing molecules, enhancing sensitivity and transparency, enabling faster response times and lower detection limits without the need for expensive detection equipment.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Strength

If a dense polymer binder is used to keep sensing material on the substrate, then the sensing material remains securely attached, but the response time becomes slow and detection sensitivity is reduced

Engineering Contradiction:
Improveadhesion of sensing materialVSAvoidresponse time
Core Design Contradiction:
StrengthVSSpeed

Solution Approach 1:

The patent replaces dense polymer binders with porous aerogel materials that provide both mechanical support and high permeability. The porous structure allows target molecules to diffuse rapidly throughout the sensing layer while the aerogel matrix maintains structural integrity and secures sensing material particles, thus achieving fast response times without sacrificing adhesion.

Inventive Principle:
Principle #31Porous materials

Solution Approach 2:

The patent creates a composite sensing layer combining aerogel particles with sensing material. This composite structure leverages the unique properties of aerogels (extremely low density, high porosity, large surface area) to enable rapid molecular diffusion while maintaining mechanical stability through the composite architecture.

Inventive Principle:
Principle #40Composite materials

2Strength

If a dense polymer binder is used to hold sensing material, then the material stays on substrate, but the color change becomes obscured and visibility is reduced

Engineering Contradiction:
Improveretention of sensing materialVSAvoidvisibility of color change
Core Design Contradiction:
StrengthVSIllumination intensity

Solution Approach 1:

The porous aerogel structure allows light to penetrate deeply throughout the sensing layer, enabling color changes occurring throughout the entire thickness to be visible. The low density and high porosity minimize light scattering and absorption by the binder itself, enhancing the visibility of color changes while maintaining material retention.

Inventive Principle:
Principle #31Porous materials

3Strength

If a dense polymer layer is formed by solvent evaporation, then the sensing material is固定在 substrate, but only top surface molecules are accessible to target compound

Engineering Contradiction:
Improvefixation of sensing materialVSAvoidnumber of accessible sensing molecules
Core Design Contradiction:
StrengthVSQuantity of substance

Solution Approach 1:

The porous aerogel matrix creates a three-dimensional network with interconnected pores that allow target molecules to diffuse throughout the entire sensing layer thickness. This increases the volume of sensing material accessible to target compounds from just the top surface to the entire bulk, significantly increasing the number of active sensing sites.

Inventive Principle:
Principle #31Porous materials

Solution Approach 2:

The patent transitions from a two-dimensional surface-bound sensing layer to a three-dimensional porous network. This dimensional change allows target molecules to access sensing material throughout the bulk volume rather than being limited to surface exposure, dramatically increasing the effective sensing capacity.

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

4Measurement precision

If expensive detection equipment like spectroscopes is used to detect trace contaminants, then detection sensitivity improves, but cost and power requirements increase

Engineering Contradiction:
Improvedetection sensitivityVSAvoiddetection equipment
Core Design Contradiction:
Measurement precisionVSDevice complexity

Solution Approach 1:

The patent modifies the physical parameters of the sensing matrix (density, porosity, surface area) to amplify the optical response signal. The aerogel's extremely high surface area to volume ratio and light scattering properties enhance color change visibility, allowing trace contaminant detection to be achieved with simple visual or basic optical detection rather than expensive spectroscopic equipment.

Inventive Principle:
Principle #35Parameter changes

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 polymer aerogel sensors achieve higher sensitivity and faster response times, allowing for detection of trace amounts of contaminants with increased visibility of color changes, reducing costs and eliminating the need for power-hungry equipment, while maintaining low power and portability.

Implementation Method 1

The resulting color may be compared to a standardized scale of colors that defines concentration or other characteristic of the material... The compound being detecting does not reach sensing molecules in the deeper layers because the polymer binder blocks their access

Methodology Applied
Scientific EffectDiffusion: Diffusion

Implementation Method 2

US 2006/104864 discloses an array of sensor elements formed by the incorporation of sensing materials into porous structures... The porphyrin sensing material is attached to the aerogel throughout its high surface area pore space

Methodology Applied
Scientific EffectAdsorption: Adsorption

Implementation Method 3

Colorimetric sensors generally consist of materials that change color based upon detection of a particular chemical or other materials

Methodology Applied
Scientific EffectColorimetric detection: Photochromism

Data Source

PatentEP3502670B1Environmental sensor
Publication Date: 2020.07.15 PALO ALTO RESEARCH CENTER INC
  • EP3502670B1 patent drawingFigure 1~2
  • EP3502670B1 patent drawingFigure 3

AI summary

A sensor has a transparent polymer aerogel, and sensing materials dispersed into the transparent, polymer aerogel, where the sensing materials change color in response to environmental conditions. A method of forming a sensor includes providing a substrate, forming a polymer aerogel layer on the substrate, and infusing the polymer aerogel layer with sensing molecules.