High Aspect Ratio Pillars for Liquid Chromatography Edge Effects

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Solution Overview

Problem

Chemical reactors, particularly those using liquid chromatography, face edge effects due to asymmetrical flow behavior at the column edges, leading to band broadening and reduced performance, which existing solutions attempt to mitigate by adjusting column designs but often at the cost of increased interpillar distance and limited manufacturing constraints.

Innovation Solution

The use of pillar structures with a high width-to-length aspect ratio in fluid channels, where the smallest distance between the channel wall and a pillar is greater than the interpillar distance, reduces edge effects and allows for compact designs without limiting interpillar distance, thereby minimizing dispersion and achieving uniform retention times.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If the width of the passage at the edge of the column is adjusted to compensate for edge effects, then edge effects are reduced, but the interpillar distance is limited and manufacturing flexibility is reduced

Engineering Contradiction:
Improvechromatography column performanceVSAvoidcolumn design complexity
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The invention changes the geometric parameters of the pillar structures, specifically using a width-to-length ratio of at least 7 (preferably at least 10), which fundamentally alters the flow dynamics and eliminates edge effects without requiring complex adjustments to passage widths or interpillar distances

Inventive Principle:
Principle #35Parameter changes

Solution Approach 2:

The invention applies a specific local geometric configuration at the edge of the column where pillars with high aspect ratios are positioned such that their long sides are parallel to the channel wall, creating a local flow pattern that compensates for edge effects and eliminates the need for different designs at the edge versus the center

Inventive Principle:
Principle #3Local quality

2Manufacturing precision

If the interpillar distance is reduced to improve separation efficiency, then dispersion increases due to edge effects, but reducing interpillar distance further is limited by manufacturing constraints

Engineering Contradiction:
Improveseparation efficiencyVSAvoidmanufacturing feasibility
Core Design Contradiction:
Manufacturing precisionVSEase of manufacture

Solution Approach 1:

By changing the pillar width-to-length ratio to at least 7, the invention enables smaller interpillar distances without the negative effects of edge-induced dispersion, pushing the boundaries of what is manufacturable while maintaining separation efficiency

Inventive Principle:
Principle #35Parameter changes

Solution Approach 2:

The specific pillar geometry and arrangement are designed in advance to preemptively counteract edge effects before they can cause dispersion, allowing interpillar distances to be minimized without suffering from the usual edge-effect penalties

Inventive Principle:
Principle #9Preliminary anti-action

3Reliability

If pillar structures with high width-to-length ratio are used, then edge effects are reduced and separation efficiency is enhanced, but the column length must be reduced for compact design

Engineering Contradiction:
Improveseparation performanceVSAvoidcolumn length
Core Design Contradiction:
ReliabilityVSLength of stationary object

Solution Approach 1:

The invention uses pillars with width-to-length ratio of at least 7 to dramatically improve flow uniformity and eliminate edge effects, which allows achieving high separation efficiency in a compact column length by reducing the need for long columns to compensate for dispersion

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 significantly reduces or eliminates edge effects, enhances separation efficiency, and allows for compact reactor designs with reduced column length, maintaining high pressure and separation performance without additional dispersion.

Implementation Method 1

an ordered set of pillar structures positioned in the channel, wherein the individual pillar structures have a length in a direction of the longitudinal axis of the channel and a width in a direction perpendicular to the longitudinal axis, and in which the individual pillar structures have a width to length ratio of at least 7

Methodology Applied
Scientific EffectFluid flow:

Data Source

PatentEP2953716B1Chemical reactor device
Publication Date: 2017.05.03 PHARMAFLUIDICS NV
  • EP2953716B1 patent drawingFigure 1~2
  • EP2953716B1 patent drawingFigure 3~4
  • EP2953716B1 patent drawingFigure 5~7

AI summary

A chemical reactor (100) is described comprising a substrate (110) with a fluid channel (120) and a set of organized pillar structures (130) positioned in the channel (120). The individual pillar structures (130) have a length in the longitudinal direction of the channel (120) and a width in the width direction of the channel (120) whereby their width-to-length aspect ratio is at least 7.