Potentiometric Gas Sensor Array with Temperature-Controlled Electrodes
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Solution Overview
Problem
Current solid-state potentiometric gas sensors lack selectivity and cross-sensitivity, particularly in distinguishing between NO and NO2 in combustion exhausts, requiring expensive electronics and complex designs, and are limited by the use of pseudo-reference electrodes that do not represent a true reference state.
Innovation Solution
The implementation of a gas sensor array with sensing electrodes maintained at different temperatures, allowing for fine-tuning of sensitivity and species selectivity, and using a mechanism to establish temperature differences between electrodes, including the use of heating and cooling elements to control electrode temperatures and improve signal interference.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If multiple sensing electrodes are used to detect different gas species, then measurement precision is improved, but device complexity increases
Solution Approach 1:
The patent applies parameter changes by maintaining different temperatures at different sensing electrodes to achieve selective detection. By controlling the temperature parameter of each electrode independently, the sensor can selectively determine different gas species (NO and NO2) without requiring multiple complex electrode configurations. This resolves the contradiction by improving measurement precision through temperature parameter control rather than increasing device complexity.
2Adaptability or versatility
If temperature control mechanisms are added to sensing electrodes, then selectivity is improved, but device complexity increases
Solution Approach 1:
The patent implements local quality by applying temperature control locally to specific sensing electrodes rather than uniformly to the entire sensor. Each electrode can be maintained at a different temperature to optimize its response to particular gas species. This localized approach improves species selectivity while minimizing the overall complexity of the temperature control system.
3Ease of manufacture
If pseudo-reference electrodes are used, then ease of manufacture is improved, but measurement precision deteriorates
Solution Approach 1:
The patent extracts the reference electrode from the sensing environment by placing it in a separate chamber isolated from the gas mixture. This allows the use of a simple pseudo-reference electrode for ease of manufacture while maintaining measurement precision, as the reference electrode is not exposed to the varying gas concentrations that would affect its potential.
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
This approach enhances the ability to selectively determine NO and NO2 concentrations, reducing the number of electrodes needed, lowering costs, and improving device performance in harsh environments, while maintaining stability and accuracy in gas mixture analysis.
Implementation Method 1
a mechanism configured to establish a temperature difference between the at least two LCO electrodes
Implementation Method 2
Potentiometric gas sensors based on measuring the potential difference between a semiconducting metal oxide and a noble metal pseudo-reference electrode
Data Source
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AI summary
Embodiments of the subject invention relate to a gas sensor and method for sensing one or more gases. An embodiment incorporates an array of sensing electrodes maintained at similar or different temperatures, such that the sensitivity and species selectivity of the device can be fine tuned between different pairs of sensing electrodes. A specific embodiment pertains to a gas sensor array for monitoring combustion exhausts and/or chemical reaction byproducts. An embodiment of the subject device related to this invention operates at high temperatures and can withstand harsh chemical environments. Embodiments of the device are made on a single substrate. The devices can also be made on individual substrates and monitored individually as if they were part of an array on a single substrate. The device can incorporate sensing electrodes in the same environment, which allows the electrodes to be coplanar and, thus, keep manufacturing costs low. Embodiments of the device can provide improvements to sensitivity, selectivity, and signal interference via surface temperature control.