Ion Mobility Spectrometer Shutter Gate Grid Parallelism Adjustment
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Solution Overview
Problem
Ion mobility spectrometers face challenges in achieving high mechanical precision for the shutter gate grid, leading to increased costs, charge-up issues, and reduced resolution due to complex structures and insulative materials close to ion flow, as well as diffusion gas flow limitations.
Innovation Solution
The ion mobility spectrometer employs a simple structure with conductive disc-shaped members and an insulation sheet, secured by insulative screws, allowing precise adjustment of grid electrode separation and parallelism, reducing charge-up risks, and enhancing assembly ease, while ventilation holes ensure uniform diffusion gas flow.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If complex structures with insulative materials are used for the shutter gate grid, then mechanical precision can be improved, but charge-up issues occur and device complexity increases
Solution Approach 1:
The patent applies homogeneity by making both grid electrodes completely conductive with uniform material composition, eliminating the heterogeneous structure of insulative materials that causes charge-up. This ensures consistent electrical properties across the entire electrode surface while maintaining mechanical precision through the conductive nature of the materials.
Solution Approach 2:
The patent uses composite material strategy by selecting conductive materials with specific properties - grid electrodes made of conductive metal materials that provide both mechanical precision and electrical conductivity. The conductive material composition prevents charge-up while maintaining the required manufacturing precision for the shutter gate grid structure.
2Manufacturing precision
If complex structures are used for the shutter gate grid, then mechanical precision can be improved, but device complexity and assembly costs increase
Solution Approach 1:
The patent applies segmentation by dividing the shutter gate grid into two independent conductive grid electrodes that can be manufactured and adjusted separately. This modular approach allows for precise positioning and assembly while simplifying the overall structure compared to integrated complex designs. The segmented conductive electrodes are arranged in parallel with controlled spacing to achieve the required mechanical precision.
Solution Approach 2:
The patent extracts the insulative materials from the grid electrode structure, leaving only the essential conductive components. This extraction simplifies the device structure by removing unnecessary insulative elements that contribute to complexity and assembly difficulty, while the conductive grid electrodes themselves provide the required mechanical precision through their simplified design.
3Reliability
If insulative materials are placed close to ion flow, then electrical insulation is improved, but charge-up occurs and resolution is reduced
Solution Approach 1:
The patent applies homogeneity by using uniform conductive materials for both grid electrodes, eliminating the insulative material layer that causes charge-up when exposed to ion flow. This homogeneous conductive structure maintains electrical insulation through the conductive properties of the materials while preventing charge-up accumulation, thereby preserving measurement resolution.
4Ease of manufacture
If simple structures are used for the shutter gate grid, then assembly ease and cost are improved, but mechanical precision deteriorates
Solution Approach 1:
The patent applies segmentation by creating a modular structure with two separate conductive grid electrodes that can be assembled independently. This segmentation simplifies the manufacturing process and assembly procedures while allowing for precise positioning of each electrode. The parallel arrangement of conductive wires in each electrode maintains the required mechanical precision through the modular design.
Solution Approach 2:
The patent uses parameter changes by carefully controlling the spacing and arrangement parameters of the conductive wires in the segmented grid electrodes. By optimizing parameters such as wire diameter, wire spacing, and electrode separation distance, the patent achieves high mechanical precision while maintaining a simple, easy-to-assemble structure with conductive materials.
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 achieves stable ion pulse widths, improved resolution, reduced assembly costs, and minimized charge-up, ensuring high analytical precision and reliability.
Implementation Method 1
When voltage is applied to the grid electrodes 12a, 12b so as to make the potential of the rear grid electrode 12b several hundred V higher than the potential of the front grid electrode 12a, the shutter gate grid 12 assumes a substantially closed state (see FIG. 7 (c)) as a result of this potential barrier, and the ions are blocked by the shutter gate grid 12.
Implementation Method 2
Furthermore, while not illustrated, diffusion gas flow in a direction opposite to the ion travel direction is formed in the drift region 11, and the ions move while colliding with this diffusion gas.
Implementation Method 3
When molecular ions generated from sample molecules are moved through a gas (or liquid) medium due to the action of an electric field, those ions move at a velocity proportional to their mobility, which is determined by the strength of the electric field, the size of the molecules, etc.
Implementation Method 4
When sample components in the sample gas are introduced into the ionization region 10, they are ionized in the ionization region 10 by the action of β rays emitted from a β ray source (63Ni, etc.) or the like.
Data Source
AI summary
Shutter gate grid is a structure wherein first and second disc-shaped members made of metal with an insulation sheet member sandwiched therebetween are integrally joined by means of insulative screws. Gate grids with conductive wires secured to the central openings thereof are fused onto the disc-shaped members; screw insertion holes formed in the second disc-shaped member are fan-shaped and have play in the direction of rotation, making it possible to adjust the parallelism of the conductive wires of the two members by finely adjusting the rotational position when tightening the screws. Moreover, diffusion gas can be made to flow through ventilation holes provided at common locations on each member, thus making it possible to provide uniformity of diffusion gas flow in the drift region.