Compact Gas Sensor Module Using PCB Recess for Extended Optical Path
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Solution Overview
Problem
Existing gas sensor modules are not compact enough for efficient gas concentration measurement, particularly for CO2, due to their bulky design which limits their integration and portability.
Innovation Solution
A compact gas sensor module design is achieved by integrating the radiation source and detector units onto a printed circuit board with a recessed area, allowing the radiation path to pass through or into the recess, and using a radiation capsule with reflective surfaces to enhance sensitivity and reduce overall height.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If the radiation path is extended to improve measurement sensitivity, then the gas concentration measurement precision is improved, but the overall height of the device increases
Solution Approach 1:
The radiation path is configured to extend in the lateral direction (x-y plane) rather than vertically, utilizing the recess area on the PCB to create a longer optical path without increasing device height. This dimensional transformation allows the radiation to traverse through the recess and reflect off the reflective surface, achieving extended path length while maintaining compact vertical profile.
Solution Approach 2:
The radiation cell is integrated within the recess area of the PCB, nesting the optical components within the existing board structure. The reflective surface is positioned at the bottom of the recess, creating a compact nested arrangement where the radiation path is contained within the recess volume, maximizing space utilization and reducing overall device height.
2Measurement precision
If the radiation path is extended to improve sensitivity, then the measurement precision is improved, but the device complexity increases
Solution Approach 1:
The radiation source, radiation detector, and reflective surface are integrated into a single radiation cell structure formed within the PCB recess. This merging of components into one unified cell reduces the number of separate parts and simplifies assembly, while still achieving the extended radiation path through the reflective geometry within the cell.
Solution Approach 2:
The PCB board serves multiple functions: it provides mechanical support, contains the recess structure for the radiation cell, and the recess itself acts as part of the radiation path containment. This multi-functionality reduces the need for additional separate components, simplifying the overall device structure while maintaining measurement precision.
3Device complexity
If the components are integrated onto a PCB to reduce device size, then the device complexity is reduced, but the radiation path length is limited
Solution Approach 1:
The radiation path is configured to extend in the lateral direction (x-y plane) rather than vertically, utilizing the recess area on the PCB to create a longer optical path without increasing device height. This dimensional transformation allows the radiation to traverse through the recess and reflect off the reflective surface, achieving extended path length while maintaining compact vertical profile.
Solution Approach 2:
The reflective surface is pre-positioned at the bottom of the recess during PCB fabrication, establishing the radiation path geometry in advance. This preliminary configuration of the reflective surface ensures that the radiation from the source will naturally reflect and extend the path length without requiring additional active components or complex adjustments during operation.
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 compact design enhances sensitivity and reduces the overall height of the gas sensor module, allowing for more efficient gas concentration measurement while protecting sensitive components from mechanical damage and environmental factors.
Implementation Method 1
using a radiation capsule with reflective surfaces to enhance sensitivity and reduce overall height
Implementation Method 2
at least one radiation source configured for emitting radiation; at least one radiation detector unit configured to detect at least part of said radiation
Implementation Method 3
at least one radiation detector unit configured to detect at least part of said radiation
Data Source
AI summary
A gas sensor module integrated onto a board comprising at least one radiation source configured for emitting radiation, at least one radiation detector unit configured to detect at least part of said radiation, and a radiation cell providing at least one radiation path from said radiation source to said radiation detector unit. Said board is provided with a recess and said radiation path is propagating within said recess.