Planar Ion Mobility Analyzer for High-Current Space Charge Control
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Solution Overview
Problem
Existing ion mobility spectrometers face challenges with space charge effects that limit their ability to accommodate high ion currents without performance degradation, leading to reduced sensitivity.
Innovation Solution
The ion mobility analyser features an elongated ion drift channel with alternating electrode assemblies, providing a planar symmetry that reduces space charge effects and increases ion capacity, coupled with a laminar gas flow and RF voltage configurations to focus and trap ions effectively.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Quantity of substance
If conventional ion mobility spectrometers with symmetrical drift channels are used, then the device structure is simple and easy to manufacture, but space charge effects limit the accommodation of high ion currents causing reduced sensitivity
Solution Approach 1:
The patent applies asymmetry by transforming the conventional symmetrical cylindrical drift channel into an elongated planar drift channel with rectangular cross-section. This asymmetric geometry redistributes ion trajectories and reduces space charge effects, enabling higher ion current capacity while maintaining or improving sensitivity. The elongated channel extends the drift path in one dimension while compressing it in the perpendicular dimension, creating non-uniform electric field distribution that mitigates ion-ion interactions.
Solution Approach 2:
The patent transitions from a three-dimensionally symmetric cylindrical channel to a two-dimensionally elongated planar channel. This dimensional transformation effectively adds spatial extent in the transverse direction while maintaining axial progression, allowing ions to distribute over a larger cross-sectional area. The planar geometry provides enhanced space for ion accommodation without proportionally increasing the axial length, thereby improving ion current capacity while controlling space charge effects.
2Quantity of substance
If the ion drift channel is elongated in the transverse direction to reduce space charge effects, then ion current capacity increases, but the device complexity and manufacturing difficulty increase
Solution Approach 1:
The patent segments the electrode system into multiple discrete electrode pairs arranged along the elongated drift channel. Each electrode pair independently generates electric field lines that confine ions to the planar drift path. This segmentation allows modular construction and assembly, where individual electrode modules can be manufactured separately and then combined to form the complete elongated channel structure, thereby reducing overall manufacturing complexity.
Solution Approach 2:
The patent replaces complex mechanical alignment requirements with electric field-based ion confinement. Instead of relying on precise mechanical positioning of components to maintain channel geometry, the electric fields generated by the electrode pairs naturally guide and confine ions along the elongated planar path. This substitution of mechanical precision requirements with electromagnetic field control simplifies manufacturing tolerances and assembly procedures.
3Quantity of substance
If symmetrical ring electrodes are used, then the electrode structure is simple and uniform, but space charge effects accumulate reducing ion mobility separation performance
Solution Approach 1:
The patent replaces symmetrical ring electrodes with asymmetric planar electrode pairs that create an elongated drift channel. This asymmetric configuration fundamentally alters the electric field distribution and ion trajectory patterns, preventing the accumulation of space charge effects that occur in symmetrical geometries. The elongated planar structure provides continuous ion evacuation paths that maintain separation performance even at high ion capacities.
Solution Approach 2:
The patent transitions from three-dimensionally symmetric ring electrodes to two-dimensionally elongated planar electrodes. This dimensional change creates additional spatial pathways for ion transport and distribution, allowing ions to spread out over a larger effective area. The elongated geometry provides extended drift paths in the transverse direction that enhance ion mobility separation while accommodating higher ion capacities without performance degradation.
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 design enhances the ion mobility analyser's sensitivity by accommodating higher ion currents while maintaining performance, allowing for improved ion separation and analysis.
Implementation Method 1
Each of the first and second electrode assemblies comprises a set of first electrodes, and a set of second electrodes. The electrodes in the first and second sets are arranged in an alternating pattern in the transverse direction.
Implementation Method 2
coupled with a laminar gas flow and RF voltage configurations to focus and trap ions effectively
Implementation Method 3
coupled with a laminar gas flow and RF voltage configurations to focus and trap ions effectively
Data Source
AI summary
An ion mobility analyser comprising an ion guide is provided. The ion guide defines an ion drift channel extending in an axial direction an includes first and second electrode assemblies provided on opposing sides of the ion drift channel. Each of the first and second electrode assemblies extend in the axial direction and in a transverse direction which is transverse to the axial direction. The first and second electrode assemblies are spaced apart on opposing sides of the ion drift channel by a first distance at a narrowest point along the axial direction. Each of the first and second electrode assemblies comprises a set of first electrodes, and a set of second electrodes. The electrodes in the first and second sets are arranged in an alternating pattern in the transverse direction. The alternating pattern extends in the transverse direction a second distance that is greater than the first distance.