Calconcarboxylic Acid Doped Polyaniline Humidity Sensor

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Solution Overview

Problem

Existing relative humidity sensors face challenges in cost-effectiveness and manufacturing ease while maintaining high sensitivity, particularly in detecting humidity changes efficiently.

Innovation Solution

A relative humidity sensor is developed using a sensitive layer formed from calconcarboxylic acid doped polyaniline, which is synthesized by reacting polyaniline with calconcarboxylic acid and deposited between interdigitated electrodes on a dielectric substrate, enhancing sensitivity and reducing production costs.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If traditional polyaniline is used in humidity sensors, then manufacturing is simpler, but sensitivity and charge transfer are insufficient

Engineering Contradiction:
ImprovesensitivityVSAvoiddoping process complexity
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

Calconcarboxylic acid serves as a doping intermediary that facilitates charge transfer in the polyaniline sensor. The calconcarboxylic acid molecules intercalate between polyaniline chains, creating efficient charge transport pathways that enhance sensitivity without requiring complex external doping equipment or processes.

Inventive Principle:
Principle #24Intermediary (Mediator)

Solution Approach 2:

The electrical conductivity and charge transfer parameters of polyaniline are enhanced by changing its chemical state through calconcarboxylic acid doping. This chemical modification transforms the polymer's electronic structure, increasing carrier concentration and mobility, thereby improving sensor sensitivity and response characteristics.

Inventive Principle:
Principle #35Parameter changes

2Reliability

If high-performance conductive polymers are used, then sensor sensitivity improves, but manufacturing cost increases

Engineering Contradiction:
Improvesensor performanceVSAvoidmanufacturing cost
Core Design Contradiction:
ReliabilityVSEase of manufacture

Solution Approach 1:

The sensor employs a cost-effective polyaniline-calconcarboxylic acid composite that achieves high performance through simple chemical doping rather than expensive alternative materials. The doping process uses readily available chemicals and straightforward procedures, making the high-performance sensor economically viable for mass production.

Inventive Principle:
Principle #27Cheap short-living objects (Disposable)

Solution Approach 2:

The sensor utilizes a composite material system combining polyaniline with calconcarboxylic acid. This composite approach leverages the inherent properties of both components to achieve superior charge transfer and sensitivity, while avoiding the need for expensive specialized materials or complex multi-layer structures.

Inventive Principle:
Principle #40Composite materials

3Speed

If rapid response to humidity changes is achieved, then sensor utility improves, but manufacturing complexity increases

Engineering Contradiction:
Improveresponse speedVSAvoidsensor structure complexity
Core Design Contradiction:
SpeedVSDevice complexity

Solution Approach 1:

The sensor employs a porous or highly accessible polymer matrix structure that allows rapid diffusion of water molecules to the active sensing sites. This physical structure, combined with the calconcarboxylic acid doping, enables fast charge transfer and quick response to humidity changes without requiring complex microfabrication or nanoscale structures.

Inventive Principle:
Principle #31Porous materials

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 sensor achieves high sensitivity and rapid response to humidity changes, with calconcarboxylic acid doped polyaniline nanofibers providing increased charge transfer and improved performance compared to traditional polyanilines, while being cost-effective and easy to manufacture.

Implementation Method 1

calconcarboxylic acid doped polyaniline nanofibers providing increased charge transfer

Methodology Applied
Scientific EffectCharge transfer: Conduction (electrical)

Implementation Method 2

sensitive layer formed from a composition including a doped conductive polymer. The doped conductive polymer is a calconcarboxylic acid doped polyaniline

Methodology Applied
Scientific EffectDoping: Dopants

Data Source

PatentEP3150999B1Relative humidity sensor and method of forming relative humidity sensor
Publication Date: 2017.12.13 HONEYWELL INTERNATIONAL INC
  • EP3150999B1 patent drawingFigure 1~2
  • EP3150999B1 patent drawingFigure 3~4
  • EP3150999B1 patent drawingFigure 5

AI summary

A relative humidity sensor is disclosed. The relative humidity sensor includes a first electrode and a second electrode disposed above a dielectric substrate. A sensitive layer is disposed above the first electrode and the second electrode, where the sensitive layer is formed from a doped conductive polymer. The doped conductive polymer is a reaction product of a polyaniline and calconcarboxylic acid.