Chromatographic Device Segmented Channels

Solution Overview

Problem

Designing chromatographic devices with micro or nano fluidic channels poses a challenge in creating sufficient surface area for solute retention while maintaining reasonable permeability, as increasing surface area often leads to higher pressure drops and decreased permeability.

Innovation Solution

The use of primary channels for convective flow and secondary channels for diffusive flow, with specific dimensions and configurations to optimize surface area and permeability, including varying cross-sectional areas and angles of intersection, allows for increased contact surface area without detrimental effects on permeability.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Area of stationary object

If the number of micro or nano channels is increased to increase surface area for solute retention, then the surface area is improved, but the permeability decreases and pressure drop increases

Engineering Contradiction:

Improvesurface areaVSAvoidpermeability

Core Design Contradiction:

Area of stationary objectVSReliability

Solution Approach 1:

The device is segmented into two distinct channel types: microchannels for convective flow and nanochannels for diffusive flow. This segmentation allows each channel type to be optimized for its specific function, with microchannels handling bulk transport and nanochannels providing retention surface area, thereby resolving the contradiction between surface area and permeability

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

Different regions of the device have different channel dimensions and flow characteristics. The microchannels have larger dimensions optimized for convective flow and low pressure drop, while the nanochannels have smaller dimensions optimized for diffusive flow and solute retention. This local differentiation allows the system to achieve both high surface area and acceptable permeability

Inventive Principle:

Principle #3Local quality

2Area of stationary object

If the number of micro or nano channels is increased to increase surface area for solute retention, then the surface area is improved, but the pressure drop increases

Engineering Contradiction:

Improvesurface areaVSAvoidpressure drop

Core Design Contradiction:

Area of stationary objectVSStress or pressure

Solution Approach 1:

The device is segmented into two distinct channel types: microchannels for convective flow and nanochannels for diffusive flow. This segmentation allows each channel type to be optimized for its specific function, with microchannels handling bulk transport and nanochannels providing retention surface area, thereby resolving the contradiction between surface area and permeability

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

Different regions of the device have different channel dimensions and flow characteristics. The microchannels have larger dimensions optimized for convective flow and low pressure drop, while the nanochannels have smaller dimensions optimized for diffusive flow and solute retention. This local differentiation allows the system to achieve both high surface area and acceptable permeability

Inventive Principle:

Principle #3Local quality

3Device complexity

If micro or nano fluidic channels are used instead of packed particles, then the device complexity is reduced, but the surface area for solute retention is insufficient

Engineering Contradiction:

Improvedevice complexityVSAvoidsurface area

Core Design Contradiction:

Device complexityVSArea of stationary object

Solution Approach 1:

The invention transitions from two-dimensional planar channels to three-dimensional integrated channel networks. The orthogonal arrangement of microchannels and nanochannels creates a three-dimensional structure that increases surface area while maintaining fabricability through standard semiconductor manufacturing processes, thus resolving the contradiction between device complexity and surface area

Inventive Principle:

Principle #17Another dimension (Dimensionality change)

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 chromatographic devices with high surface area and acceptable permeability, facilitating effective chromatographic separation without impractical pressure drops, by utilizing micro and nano scaled channels with convective and diffusive flow regimes.

Implementation Method 1

one or more primary channels in which convective fluidic flow dominates the flow of the mobile phase

Methodology Applied

Scientific EffectConvection: Convection

Implementation Method 2

a plurality of secondary channels, intersecting a primary channel, in which diffusive flow dominates the flow of the mobile phase

Methodology Applied

Scientific EffectDiffusion: Diffusion

Implementation Method 3

Analytes in the mobile phase are transported along the primary channel and diffuse into and out of secondary channels, interacting with the surface of the secondary channels and thereby, at least in part, being chromatographically separated

Methodology Applied

Scientific EffectChromatography: Chromatography

Data Source

PatentUS11041834B2High surface area chromatographic device with low pressure drop

Publication Date: 2021.06.22 WATERS TECHNOLOGY CORP

AI summary

A chromatographic device includes a primary channel having a cross-sectional area and characteristic length such that analyte travel within the primary channel is substantially convective. A plurality of secondary channels each having a cross-sectional area and characteristic length such that analyte flow into and out of a secondary channel is substantially diffusive, each of the plurality of secondary channels having an entrance in fluidic communication with the primary channel wherein the entrance intersects the primary channel.