Micro-Colorimetric Sensor with Parallel Linear Channels for Continuous Gas Monitoring
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Solution Overview
Problem
Traditional colorimetric gas sensors are limited by their one-time use due to irreversible chemical reactions, poor selectivity, high power consumption, and mechanical components that wear out over time, leading to inaccurate chemical sensing and short sensor lifetimes.
Innovation Solution
A micro-colorimetric sensor with parallel linear channels of porous media coated with sensing chemicals, where air samples diffuse passively, creating a slow and sharp color gradient that can be tracked using a CMOS imager and imaging processing algorithm, allowing for continuous monitoring of multiple chemicals without mechanical motors or pumps.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Duration of action of moving object
If mechanical motors or pumps are used to rotate sensor strips or force air flow, then continuous monitoring capability is achieved, but device complexity, energy consumption, and size increase
Solution Approach 1:
The patent removes mechanical motors and pumps from the sensor system, extracting the active transport mechanism entirely. Instead, it relies on passive diffusion through carefully designed microchannels to achieve continuous monitoring, thereby reducing device complexity while maintaining extended sensor lifetime
Solution Approach 2:
The sensor system performs self-service by using natural diffusion processes rather than externally powered mechanical components. The microchannel structure itself facilitates the continuous movement of analytes across the sensing surface without requiring additional energy input or mechanical actuation
2Duration of action of moving object
If mechanical motors or pumps are used to rotate sensor strips or force air flow, then continuous monitoring capability is achieved, but energy consumption increases
Solution Approach 1:
The patent extracts and eliminates the energy-consuming mechanical components (motors and pumps) from the system. Continuous monitoring is achieved through passive diffusion, which requires no external energy input, thereby dramatically reducing energy consumption while extending sensor operational lifetime
Solution Approach 2:
The system utilizes natural diffusion processes that occur spontaneously without energy input. The microchannel geometry is designed to facilitate continuous analyte transport across the sensing surface through concentration gradients alone, making the system self-powered and energy-efficient
3Duration of action of moving object
If mechanical motors or pumps are used to rotate sensor strips or force air flow, then continuous monitoring capability is achieved, but device size increases
Solution Approach 1:
The patent removes bulky mechanical components (motors, pumps, and associated drive mechanisms) from the device. The resulting miniaturized sensor relies on passive diffusion through microchannels, enabling continuous monitoring functionality in a compact form factor suitable for portable and wearable applications
4Duration of action of moving object
If mechanical motors or pumps are used, then continuous monitoring is achieved, but mechanical wear causes rotation speed and flow rate to vary over time, leading to sensing errors
Solution Approach 1:
The patent eliminates mechanical moving parts that are subject to wear and degradation. By using passive diffusion through fixed microchannel structures, the system achieves continuous monitoring without the reliability issues associated with mechanical wear, ensuring consistent sensing accuracy over extended operational periods
Solution Approach 2:
The system uses inherent diffusion processes that are not subject to mechanical wear or degradation. The diffusion-driven transport mechanism maintains consistent performance over time without requiring calibration or replacement of moving components, thereby improving long-term reliability and sensing accuracy
5Measurement precision
If colorimetric sensors are used, then selectivity for target analytes is improved, but the sensors are limited to one-time use due to irreversible chemical reactions
Solution Approach 1:
The patent divides the sensing surface into multiple discrete microchannels, each containing sensing chemicals that react with target analytes. As analytes diffuse through the channels, they react with sensing materials in sequence from inlet to outlet, creating a spatial progression of color changes that enables continuous monitoring across multiple channels while maintaining the selectivity of individual colorimetric reactions
Solution Approach 2:
The patent transitions from temporal reuse (attempting to regenerate a single sensing surface) to spatial multiplication by creating multiple parallel microchannels. Each channel provides a fresh sensing pathway, allowing continuous monitoring by progressing through the spatial dimension of multiple channels rather than attempting temporal regeneration
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
Enables long-term, continuous monitoring of airborne chemicals with improved selectivity and accuracy, reducing energy consumption and device size, while maintaining sensitivity and detection limits.
Implementation Method 1
air samples diffuse passively
Implementation Method 2
reaction of the chemical with a component in the medium to produce a distinct color change
Data Source
AI summary
A micro-colorimetric sensor for sensing target chemicals using edge tracking includes a substrate. A plurality of parallel linear channels of porous media is entrenched into the substrate and each linear channel includes a sensing material adapted to sense one of several specific target chemicals in air. The plurality of parallel linear channels is separated by barrier material from the adjacent parallel linear channel where the barrier material blocks diffusion of chemicals from one linear channel to another. A plate is affixed over the substrate top to cover the plurality of parallel linear channels. An air sample is diffused along the micro-colorimetric sensor and color images are captured. An intensity profile is derived from the plurality of color images to determine a maximum and a minimum intensity value along the sensor. A plurality of positions along the sensor is tracked to determine an edge position.