Multi-bridge Gas Sensor for Simultaneous Electrical and Thermal Analysis
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing gas sensors lack the capability to simultaneously measure electrical and thermal properties of gases, limiting their accuracy and reliability in gas analysis.
Innovation Solution
A sensor design featuring multiple bridge structures with hotplates and integrated circuitry that allows for dual operation modes: one for measuring electrical properties of metal oxide patches and another for measuring thermal properties of gases, such as thermal capacity, conductivity, and diffusivity, using the same substrate.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If a single hotplate with sensing material is used, then the device complexity is reduced, but the measurement precision is insufficient because only electrical properties can be measured
Solution Approach 1:
The sensor is divided into multiple independent bridge structures, each with its own hotplate and sensing capabilities. The first bridge structure measures electrical properties of gases through metal oxide sensing material, while the second bridge structure measures thermal properties through temperature sensors. This segmentation allows simultaneous multi-parameter measurement without interfering with each other's functionality.
Solution Approach 2:
The sensor system is designed to perform multiple functions using a unified platform. Both bridge structures share common elements such as the substrate, recess architecture, and heater circuitry, while enabling diverse measurement capabilities including electrical conductivity measurement and thermal property measurement (thermal capacity, thermal conductivity, thermal diffusivity) of gases.
2Measurement precision
If multiple separate sensors are used to measure different gas properties, then the measurement precision improves, but the device complexity increases
Solution Approach 1:
Multiple sensing functionalities are merged into a single integrated sensor device. The first and second bridge structures are positioned side-by-side within the same substrate, sharing common support infrastructure including the recess, substrate mounting, and control circuitry. This merging reduces the overall system complexity compared to using separate standalone sensors while maintaining the ability to measure multiple gas properties simultaneously.
3Reliability
If thermal properties of gas are measured, then the reliability of gas analysis is improved, but additional measurement parameters require more complex circuitry
Solution Approach 1:
The control circuitry is designed with multi-functionality to handle both electrical property measurements and thermal property measurements. The same circuit board and processing unit manage the heater control, temperature sensing, and electrical conductivity measurements, reducing the need for entirely separate control systems and minimizing the increase in circuitry complexity.
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 comprehensive gas analysis by combining electrical and thermal property measurements, enhancing accuracy, reliability, and sensitivity, and allowing for simultaneous measurement of gas composition and pressure.
Implementation Method 1
a heater adapted to heat the first hotplate
Implementation Method 2
measuring an electrical property of the first patch of sensing material in dependence on a composition of a gas
Implementation Method 3
measuring a thermal property of the gas in dependence on a heating of the first hotplate; The thermal property is a thermal capacity and/or a thermal conductivity and/or a thermal diffusivity of the gas
Data Source
AI summary
The disclosure relates to a sensor for detecting and/or analysing a gas. The sensor comprises a substrate, a recess or opening arranged in the substrate, a first bridge structure and a second bridge structure. The first bridge structure and the second bridge structure extend over said recess or opening and are anchored in the substrate. The first bridge structure forms a first hotplate and comprises a first patch of sensing material, in particular of a metal oxide material, arranged on the first hotplate, electrodes adapted to measure an electrical property of the first patch and a heater adapted to heat the first hotplate. The second bridge structure comprises a temperature sensor. The sensor comprises circuitry for driving the heater and for processing signals from the electrodes and the temperature sensor. The sensor provides a first operation mode configured to perform a measurement of an electrical property of the first patch and a second operation mode configured to operate the second bridge structure in a sensing mode to perform a measurement of a thermal property of the gas. The thermal property is a thermal capacity and/or a thermal conductivity and/or a thermal diffusivity of the gas.