Concave Particulate Matter Sensor Electrode Configuration
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Solution Overview
Problem
Conventional particulate matter detection sensors in exhaust gas purification devices face reduced collection efficiency and detection sensitivity due to particulate matter rebounding from the substrate, especially on protruding parts where the distance between the surface and detection electrodes is long, leading to inadequate collection and detection of particulate matter.
Innovation Solution
A particulate matter detection sensor with a concave collection part and detection electrodes arranged in a specific configuration to trap and collect particulate matter efficiently, featuring a concave shape with inclined surfaces and alternating detection and insulation layers to enhance collection and detection sensitivity.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Device complexity
If a flat substrate with protruding parts is used, then the structure is simple, but the collection rate of particulate matter decreases due to rebound
Solution Approach 1:
The substrate surface is changed from flat to concave curved shape, creating a collection groove that traps particulate matter. The concave curvature causes particles to collide with the surface at angles that promote deposition rather than rebound, significantly improving the collection rate while maintaining structural simplicity.
2Reliability
If the distance between protruding part surface and detection electrodes is increased, then the electrodes are better protected, but the collection efficiency of particulate matter decreases
Solution Approach 1:
The detection electrodes are selectively positioned only in the bottom region of the concave collection groove, not uniformly across the entire substrate. This local placement ensures electrodes are protected by the concave structure while maintaining short distances for effective particle collection and detection in the critical accumulation zone.
3Productivity
If a concave collection part is formed, then the collection rate increases, but the device complexity increases
Solution Approach 1:
The concave collection groove is formed by simple curvature of the substrate surface, creating an effective particle trap without requiring complex multi-component structures. The curved geometry achieves enhanced collection performance through fundamental shape modification rather than adding complex mechanical or electrical systems.
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
The sensor design significantly increases the collection rate and detection sensitivity by reducing particulate matter rebound and improving the likelihood of collision and deposition on the concave collection part, even at higher exhaust gas flow speeds.
Implementation Method 1
The particulate matter detection sensor is configured to change an output electrical signal due to electrical properties between the pair of the detection electrodes when the particulate matter are deposited on the deposition part
Implementation Method 2
The deposition part has a concave collection part formed in a concave shape... improving the likelihood of collision and deposition on the concave collection part
Data Source
AI summary
A particulate matter detection sensor has an element part for detecting an amount of PM contained in exhaust gas emitted from an internal combustion engine. A deposition part and at least a pair of detection electrodes are formed on an end surface of the element part. Some of particles of PM is deposited on the deposition part. The pair of detection electrodes are arranged on the deposition part. The particulate matter detection sensor changes its output electrical signal according to variation of electrical properties between the pair of the detection electrodes due to deposition of PM on the deposition part. A concave collection part is formed on the deposition part. The concave collection part has a concaved shape when viewed from the edge surface of the element part.