Shaped Electrospray Emitter for Stable Multi-Plume Ionization

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Solution Overview

Problem

Existing electrospray ionization (ESI) methods in mass spectrometry face limitations in ionization efficiency due to space charge repulsion between adjacent plumes, despite theoretical improvements with multiple nozzles, and there is a need for enhanced mixing between droplet streams and nebulizing gas flow.

Innovation Solution

A single nozzle emitter geometry with a shaped aperture is used to produce multiple droplet streams with defined nucleation points, utilizing electrostatic repulsion to enhance droplet mixing with a surrounding sheath gas flow, stabilizing and reproducibly directing droplets to a mass spectrometer inlet.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Quantity of substance

If multiple nozzles are used to increase ion current, then sensitivity is improved, but space charge repulsion between adjacent plumes reduces the theoretical ion current improvement

Engineering Contradiction:
Improveion currentVSAvoidspace charge repulsion
Core Design Contradiction:
Quantity of substanceVSObject-affected harmful factors

Solution Approach 1:

The single nozzle is segmented into multiple independent spray plumes through a shaped aperture with multiple emission sites, allowing each plume to operate independently while maintaining overall system compactness and avoiding space charge repulsion issues

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

Multiple spray plumes are merged into a single nozzle structure, combining the benefits of multiple nozzles (increased ion current) while eliminating the harmful interactions between separately positioned nozzles

Inventive Principle:
Principle #5Merging (Combining)

2Quantity of substance

If multiple nozzles are spaced by micron-scale dimensions, then sensitivity is improved, but droplet stream mixing with nebulizing gas flow is insufficient

Engineering Contradiction:
Improveion currentVSAvoiddroplet stream mixing
Core Design Contradiction:
Quantity of substanceVSStability of the object's composition

Solution Approach 1:

The aperture is designed with different local geometries at different emission sites, creating varied droplet trajectories and spray patterns that enhance local mixing with the nebulizing gas flow while maintaining overall system performance

Inventive Principle:
Principle #3Local quality

3Stability of the object's composition

If a single nozzle emitter with shaped aperture is used, then droplet stream mixing is enhanced, but emission stability and reproducibility must be maintained

Engineering Contradiction:
Improvedroplet stream mixingVSAvoidemission stability
Core Design Contradiction:
Stability of the object's compositionVSReliability

Solution Approach 1:

The aperture employs asymmetric curved sections with different radii of curvature to create defined nucleation points that stabilize Taylor cone formation, ensuring reproducible emission patterns while promoting droplet stream mixing through non-uniform geometry

Inventive Principle:
Principle #4Asymmetry

Solution Approach 2:

Curved sections with specific radii of curvature are used to shape the aperture, creating well-defined Taylor cone nucleation points that ensure stable and reproducible droplet emission while enhancing mixing through controlled spray trajectories

Inventive Principle:
Principle #14Spheroidality (Curvature)

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 increases ionization efficiency by promoting droplet stream mixing and desolvation, leading to improved sensitivity and robustness in electrospray ionization processes, particularly when combined with liquid chromatography.

Implementation Method 1

utilizing electrostatic repulsion to enhance droplet mixing with a surrounding sheath gas flow

Methodology Applied
Scientific EffectElectrostatic repulsion: Ion Repulsion/Attraction

Implementation Method 2

at least partially desolvating each of the plurality of non-axial droplet streams in a sheath gas flow

Methodology Applied
Scientific EffectEvaporation: Evaporation

Data Source

PatentEP4641615A1Electrospray emitter with non-uniform radius of curvature
Publication Date: 2025.10.29 THERMO FINNIGAN LLC
  • EP4641615A1 patent drawingFigure 1A~1D
  • EP4641615A1 patent drawingFigure 2A
  • EP4641615A1 patent drawingFigure 2B~2C

AI summary

Multiple droplet streams are produced with shaped apertures that are situated at distal ends of flow members. The droplet streams interact with and are desolvated by a shear gas flow. A variable number of droplet streams at fixed locations can be produced by selection of a suitable extraction electric field.