Patterned Slit Fixtures for Stable High-Throughput Electrospinning
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Solution Overview
Problem
Current needle electrospinning techniques have low throughput and are unstable over time, leading to meniscus growth and reduced polymer solidification efficiency, while slit-surface electrospinning is prone to instability and short run times.
Innovation Solution
The use of patterned slit-fixtures with S-wave or sinusoidal patterns on inner and outer walls, as well as non-curvy patterns like hexagonal or diamond shapes, to control fluid flow and electric field distribution, allowing for stable and high-throughput electrospinning by minimizing meniscus growth and lateral movement of jets.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If needle electrospinning is used, then fiber production is achieved, but throughput is low and run time is short
Solution Approach 1:
The invention divides the electrospinning process into multiple independent jet emitters arranged in an array on a slit fixture, allowing simultaneous production of multiple fiber jets. This segmentation enables high throughput while maintaining stable operation of each individual jet, resolving the contradiction between productivity and duration.
Solution Approach 2:
The patterned surface acts as an intermediary between the polymer solution and the electric field, creating controlled meniscus formation and jet emission points. This intermediary structure stabilizes the electrospinning process, enabling long run times while maintaining high throughput through multiple concurrent jets.
2Productivity
If slit-surface electrospinning is used to increase throughput, then productivity improves, but stability deteriorates and meniscus growth occurs
Solution Approach 1:
The slit fixture is equipped with patterned surfaces that create locally optimized conditions at each jet emission point. The patterns (such as triangular, rectangular, or circular geometries) locally control meniscus formation and jet stability, maintaining reliability while achieving high throughput through multiple concurrent emission points.
Solution Approach 2:
The patterned surfaces feature curved geometries (triangular, rectangular, or circular patterns) that optimize the distribution of polymer solution and electric field at each emission point. These curved patterns prevent meniscus growth by creating stable, localized menisci, thereby maintaining stability while enabling high throughput electrospinning.
3Productivity
If high voltage is applied to increase fiber emission rate, then productivity increases, but lateral movement of jets increases reducing precision
Solution Approach 1:
The patterned surface acts as an intermediary structure that anchors each jet at a predetermined location. By providing physical guidance features (patterns) on the slit fixture, the invention maintains precise jet positioning even at high emission rates, resolving the contradiction between productivity and manufacturing precision.
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 patterned slit-fixtures enhance electrospinning stability, enabling longer continuous run times and increased productivity by constraining jet formation and reducing meniscus growth, resulting in a significant improvement in efficiency and throughput.
Implementation Method 1
Exposure of a small volume of electrically conductive liquid to an electric field causes the liquid to deform from the shape established by surface tension alone
Implementation Method 2
As the voltage increases the force of the electric field approaches the surface tension of the liquid, resulting in the formation of a Taylor cone with convex sides and a rounded tip
Implementation Method 3
As the highly charged liquid jet stream travels in the air towards an electrically grounded collector it experiences bending and stretching effects due to charge repulsion
Implementation Method 4
As the volatile solvent evaporates very fine polymer fibers, typically on the micro- or nano-scale, are collected on the grounded collector
Implementation Method 5
these elements may include a variety of patterns and/or shapes that affect fluid flow through the aperture and electrical field across the aperture
Implementation Method 6
patterns and/or shapes that affect fluid flow through the aperture and electrical field across the aperture
Data Source
AI summary
The present invention relates generally to the field of electrospinning. In particular, the present invention relates to an electrospinning device that includes a slit-fixture defined by an elongate aperture disposed between opposing elements of an electrically conductive material. These elements include a variety of patterns/shapes that affect the flow of fluid through the aperture and the electrical field across the aperture.