Counterflow Ion Mobility Spectrometer for Precise Ion Trapping

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Solution Overview

Problem

Current ion chromatography and mass spectrometry systems face challenges in efficiently separating and identifying ions based on their mobility, particularly in achieving precise separation and analysis of ions with varying mobilities in complex samples.

Innovation Solution

The development of a mass spectrometry platform incorporating a trapped ion mobility spectrometer (TIMS) with a variable cross-section or mass flow, which uses a constant electric field and controlled gas flow to trap and separate ions based on their mobility, allowing for precise positioning and subsequent analysis.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Measurement precision

If a constant electric field and controlled gas flow are used to trap and separate ions, then ion separation precision is improved, but device complexity increases

Engineering Contradiction:
Improveion separation precisionVSAvoiddevice complexity
Core Design Contradiction:
Measurement precisionVSDevice complexity

Solution Approach 1:

The device is divided into distinct functional regions: a drift region with a first electrode for ion transport and a trapping region with a second electrode for ion confinement. This segmentation allows each region to be optimized independently for its specific function, achieving precise ion separation while managing overall device complexity through modular design.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

Different electric field configurations are applied in different spatial regions: a constant electric field in the drift region for controlled ion transport and a variable electric field in the trapping region for selective ion confinement. This local differentiation of field properties enables precise ion separation based on mobility while maintaining manageable device complexity through region-specific optimization.

Inventive Principle:
Principle #3Local quality

2Productivity

If variable cross-section or mass flow is implemented in the TIMS device, then ion mobility separation efficiency is improved, but manufacturing complexity increases

Engineering Contradiction:
Improveion mobility separation efficiencyVSAvoidmanufacturing complexity
Core Design Contradiction:
ProductivityVSEase of manufacture

Solution Approach 1:

The device incorporates variable cross-section geometry or variable mass flow characteristics that create position-dependent drag forces on ions. This dynamic configuration allows different regions of the device to provide different separation efficiencies, improving overall ion mobility separation efficiency while the variable parameters are built into the device structure to avoid excessive manufacturing complexity.

Inventive Principle:
Principle #15Dynamics

3Measurement precision

If multiple electrodes with variable electric fields are used, then ion positioning accuracy is improved, but energy consumption increases

Engineering Contradiction:
Improveion positioning accuracyVSAvoidenergy consumption
Core Design Contradiction:
Measurement precisionVSUse of energy by moving object

Solution Approach 1:

The device uses multiple electrodes capable of independent voltage control to create variable electric field configurations. By changing electric field parameters (strength and distribution) rather than physical device parameters, the system achieves precise ion positioning accuracy while avoiding the high energy consumption that would result from mechanical reconfiguration or continuous high-field application throughout the entire device.

Inventive Principle:
Principle #35Parameter changes

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 approach enables effective separation and analysis of ions with varying mobilities, improving the accuracy and efficiency of ion identification and characterization in mass spectrometry systems.

Implementation Method 1

IMS is an analytical technique used to separate and identify ionized molecules in the gas phase based on their mobility in a carrier buffer gas

Methodology Applied
Scientific EffectIon mobility: Electrophoresis

Implementation Method 2

A gas flow can be supplied into a first end of the ion mobility separator

Methodology Applied
Scientific EffectGas flow transport: Advection

Implementation Method 3

an electric field can be created between a first electrode and a second electrode of the ion mobility separator

Methodology Applied
Scientific EffectElectrical force: Lorentz Force

Data Source

PatentEP3889595B1Counterflow uniform-field ion mobility spectrometer
Publication Date: 2024.07.17 THERMO FINNIGAN LLC
  • EP3889595B1 patent drawingFigure 1
  • EP3889595B1 patent drawingFigure 2A~2B
  • EP3889595B1 patent drawingFigure 3A~3B

AI summary

An ion mobility device includes a plurality of electrodes and a current source. The plurality of electrodes arranged along an axis extending from a first end to a second end. The plurality of electrodes configured to receive a gas flow at the second end and provide for an expansion of the gas flow from the second end to the first end such that a first gas velocity at the second end is greater than a second gas velocity at the first end, for example wherein the plurality of electrodes forms a channel having a cross section that increases from the second end to the first end, wherein at least a subset of the plurality of electrodes create flow paths for the gas flow away from the channel or wherein at least a subset of the plurality of electrodes have a decreasing length or diameter going in the direction from the second end to the first end.The current source is configured to apply a first potential to the plurality of electrodes to generate a first electric field during a trapping and equilibration time period; and apply a second potential to the electrodes during an ejection time period to generate a second electric field, the second electric field being greater than the first electric field.