Gas Characterization System Using Preconcentrator Modules
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Conventional gas sensors lack the necessary resolution and selectivity to accurately characterize or classify gas mixtures, particularly in mobile and consumer applications, where cost, size, speed, and power consumption are critical factors, and often struggle to differentiate between similar volatile organic compounds.
Innovation Solution
A gas characterization system comprising preconcentrator modules with integral heaters and gas adsorbent materials, in fluid communication with gas sensor modules, which adsorb and release gases at varying temperatures, providing a two-dimensional response for analysis and classification.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If conventional gas sensors are used to detect gas mixtures, then the system is simple and low cost, but the resolution and selectivity are insufficient to accurately characterize or classify gas mixtures
Solution Approach 1:
The gas sensor array is segmented into multiple sensors, each with different metal oxide materials having distinct selectivity characteristics. This segmentation allows the system to differentiate between various volatile organic compounds by measuring the unique response pattern across the segmented sensor population, thereby improving gas mixture characterization resolution without requiring a single complex sensor.
Solution Approach 2:
Different metal oxide materials are combined in the sensor array to create a composite sensing system. Each metal oxide material provides different responses to gases, and the composite response from multiple materials enables the system to achieve higher selectivity and resolution for gas mixture characterization compared to individual sensors.
2Measurement precision
If gas sensors with varied selective responses are used, then chemical selectivity is improved, but many chemicals still have similar temperature-dependent responsivities limiting practical selectivity
Solution Approach 1:
The system adds a temporal dimension to the measurement by performing temperature scans over time. Instead of relying solely on static temperature-dependent responsivities that often overlap, the system measures the dynamic response pattern across time as temperature changes, creating a two-dimensional response matrix that provides additional discrimination capability between chemicals with similar temperature responses.
Solution Approach 2:
The operating temperature of the metal oxide sensors is dynamically changed during measurement. By scanning through a range of temperatures and recording the response at each temperature point, the system exploits the changing selectivity characteristics at different temperatures to achieve better chemical discrimination than at a single fixed temperature.
3Measurement precision
If lab analytical equipment is used for gas characterization, then measurement accuracy is high, but the equipment is not compact, expensive, and consumes excessive power
Solution Approach 1:
Multiple gas sensors with different metal oxide materials are merged into a single integrated array that shares common structural and control elements. This merging approach enables the system to achieve laboratory-grade analytical capability for gas mixture characterization while maintaining a compact form factor and reducing overall power consumption compared to using separate lab equipment for each measurement function.
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
Enhances the resolution and selectivity of gas characterization by allowing for the separation and measurement of gas mixtures based on volatility and reactivity, enabling the detection of smaller concentrations and improving chemical discrimination.
Implementation Method 1
a surface on which is deposited a gas adsorbent. The gas adsorbent material is typically porous and capable of adsorbing gases that come in contact with the material, especially volatile organic compounds
Implementation Method 2
An integral heater element of the preconcentrator can be used to increase the temperature of the preconcentrator to release adsorbed gases from the gas adsorbent material
Data Source
AI summary
Disclosed herein are embodiments of a gas sensor system and methods of analyzing data therefrom. In embodiments, a gas sensor system includes one or more gas preconcentrator modules and one or more gas sensor modules. Each gas preconcentrator module includes a substrate that has a top surface having a gas adsorbent material attached to the top surface and has an electrical heater element for heating each preconcentrator module to release adsorb gases to the sensor. The gas sensor modules and the gas preconcentrator modules are in fluid communication with each other. The gas sensor modules responses are readout in parallel multiple times as the preconcentrators are heated yielding a 2-dimensional gas spectrum. The gas sensor output data is analyzed and compared to a library of known data to analyze the gas composition.