Electrospray Emitter Arrays for Stable Long-Life Propellant Emission
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Current electrospray emitters suffer from short lifetimes, off-axis emission, poor stability, and electrical current limitations, which hinder their effectiveness in spacecraft propulsion and other applications.
Innovation Solution
A new apparatus featuring emitter arrays with controlled emitter parameters, such as uniformity, narrow pore size distribution, and controlled electric fields, enhances stability and emission control, enabling long lifetime and predictable propellant spray.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Duration of action of moving object
If conventional electrospray emitters are used, then emission is achieved, but lifetime is short and stability is poor
Solution Approach 1:
The emitter is segmented into multiple capillaries arranged in an array, where each capillary operates independently. This segmentation allows the system to maintain stable emission from multiple channels even if individual capillaries degrade or fail, thereby extending overall emitter lifetime while maintaining reliability through redundant operational channels.
Solution Approach 2:
The invention changes the geometric parameters of the emitter, specifically using capillaries with diameter ratios (d/D) between 0.05 and 0.5, and aspect ratios (h/d) between 1 and 100. These parameter optimizations ensure uniform electric field distribution and stable electrospray emission, improving both lifetime and reliability by preventing localized field breakdown and ensuring consistent performance across all capillaries.
2Ease of operation
If conventional electrospray emitters are used, then emission occurs, but off-axis emission and poor directionality result
Solution Approach 1:
Each capillary in the array is designed with specific local geometric qualities (controlled diameter ratios and aspect ratios) that optimize the electric field distribution at the emission tip. This local quality control ensures that emission occurs predominantly on-axis from each capillary, and the collective arrangement maintains overall directional stability, improving both ease of operation and emission directionality.
3Power
If conventional electrospray emitters are used, then emission is produced, but electrical current limitations occur
Solution Approach 1:
The electrical current capacity is increased by segmenting the emitter into multiple capillaries that operate in parallel. Each capillary carries a portion of the total current, allowing the system to handle higher overall electrical currents without requiring a single complex high-current emitter structure. This segmentation approach increases power capacity while maintaining relatively simple individual capillary structures.
Solution Approach 2:
Multiple simple capillary structures are merged into a unified emitter array that functions as a single high-capacity emission device. By combining the electrical current capacity of multiple capillaries while maintaining their individual simplicity, the system achieves high power capacity without the complexity of a single large-scale emitter structure.
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 apparatus achieves high stability and controlled emission, extending emitter lifetime and improving propellant spray uniformity, suitable for spacecraft propulsion and other applications like biomedical injection needles and ion beam sources.
Implementation Method 1
Apparatus for electrospray emission comprising one or more emitter arrays
Implementation Method 2
controlled electric fields, enhances stability and emission control
Data Source
AI summary
An electrospray apparatus including a plurality of emitters, disposed on a substrate, wherein the plurality of emitters can have a narrow parameter distribution.