Gas Sensor With Opposite-Side Catalytic Surfaces
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing sensors for detecting oxidizable gases require a large amount of space and high energy due to the arrangement of catalytically active and inactive surfaces on the same side of a hot plate, leading to increased energy demand and reduced accuracy.
Innovation Solution
The catalytically active and inactive surfaces are arranged on different sides of a hot plate connected via a thermal element, utilizing the Seebeck effect to measure the temperature difference directly, allowing for a compact design with reduced energy consumption and improved accuracy using materials with high Seebeck coefficients and ceramic conductors.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Device complexity
If the catalytically active and inactive surfaces are arranged on the same side of the hot plate, then the sensor structure is simpler, but the sensor requires a large amount of space and has high energy demand
Solution Approach 1:
The patent transitions from a planar arrangement where both surfaces are on the same side to a three-dimensional configuration where surfaces are positioned on opposite sides of the hot plate. This spatial reorganization reduces the sensor's footprint while maintaining functional integrity, directly resolving the contradiction between structural simplicity and compact size.
2Device complexity
If the catalytically active and inactive surfaces are arranged on the same side of the hot plate, then the sensor structure is simpler, but the energy demand increases
Solution Approach 1:
By positioning surfaces on opposite sides of the hot plate rather than on the same side, the patent reduces the thermal mass required and optimizes heat distribution. This dimensional reconfiguration decreases the energy needed to maintain the hot plate at operating temperature while preserving the simplified structural approach.
3Stability of the object's composition
If the catalytically active surface is located on a heat-transfer body next to the inactive surface, then thermal isolation is improved, but the sensor requires a relatively large amount of space
Solution Approach 1:
The patent merges the hot plate structure with the mounting arms that provide thermal isolation. The narrow arms serve dual functions: mechanically supporting the hot plate while providing thermal isolation between the active and inactive surfaces. This consolidation eliminates the need for separate isolation structures, reducing overall sensor volume while maintaining thermal stability.
4Device complexity
If the temperature difference is measured indirectly, then the measurement device is simpler, but the measurement precision decreases
Solution Approach 1:
The patent introduces a thermoelectric element as an intermediary between the hot plate surfaces and the measurement device. This element directly converts the temperature difference into an electrical signal through the Seebeck effect, providing precise measurements while keeping the overall device relatively simple. The thermoelectric element acts as a transducer that bridges the thermal and electrical domains.
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 configuration enables a sensor with a significantly reduced space requirement and lower energy demand while maintaining or improving detection accuracy for oxidizable gases, such as hydrocarbons, carbon monoxide, and hydrogen, by measuring thermoelectric voltage between the surfaces.
Implementation Method 1
The difference in temperature between the two surfaces may be measured directly (that is to say through the cross section of the sensor element) by utilizing the Seebeck effect. The Seebeck effect is based on the formation of an electrical voltage if there is a difference in temperature across a test material.
Implementation Method 2
If a reducing gas, for example H2, C3H6, is present in the surroundings (assuming there is also oxygen present in the surroundings), the corresponding gas will oxidize on the surface of the catalytically active material. This exothermal reaction raises the temperature of this section
Data Source
AI summary
A sensor for detecting oxidizable gases may comprise a catalytically inactive surface and a catalytically active surface on opposite sides of a sensor element and a thermal element running through the sensor element to connect the two surfaces, with a device for measuring a thermoelectric voltage between the catalytically active surface and the inactive surface as a measure of the difference in temperature and therefore the gas concentration. The sensor may include a hot plate mounted on a base carrier by means of narrow arms, wherein the thermal element includes at least one via extending through the hot plate and connecting the two surfaces to one another, and in the region of which the thermoelectric voltage is measured.