Microfluidic Filtering System With Counter-Flow Cleaning

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Solution Overview

Problem

Existing microfluidic filters face challenges in effectively cleaning and maintaining their functionality, especially in microfluidic applications where contaminants and larger particles can clog the filtering channels, leading to reduced efficiency and performance.

Innovation Solution

A microfluidic filtering system that employs a counter-flow of fluid, where a secondary flow is directed opposite to the primary flow to facilitate the cleaning of filtering channels by pulsed or intermittent pumping, dislodging and removing larger particles that clog the filter channels, thereby maintaining their efficiency and preventing occlusion.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If a filter is used to remove contaminants from fluid in microfluidic applications, then filtration efficiency is improved, but the filter channels become clogged with larger particles, reducing operational duration

Engineering Contradiction:
Improvefiltration efficiencyVSAvoidoperational duration
Core Design Contradiction:
ReliabilityVSDuration of action of stationary object

Solution Approach 1:

The system implements periodic reverse flow pulses to clear particulate matter from the filter channels. The controller alternates between forward flow mode (for normal filtration) and reverse flow mode (for cleaning), creating a periodic action that maintains filter efficiency over extended operational periods without requiring manual intervention or replacement.

Inventive Principle:
Principle #19Periodic action

2Duration of action of stationary object

If filter channels are cleaned by reverse flow, then operational life is extended, but system complexity increases due to additional pumping requirements

Engineering Contradiction:
Improveoperational lifeVSAvoidsystem complexity
Core Design Contradiction:
Duration of action of stationary objectVSDevice complexity

Solution Approach 1:

The same pump system is used for both forward flow (filtration) and reverse flow (cleaning) operations. The controller selectively reverses the pumping direction to achieve different functions, eliminating the need for separate cleaning pumps or additional hardware, thus extending operational life without proportionally increasing system complexity.

Inventive Principle:
Principle #6Universality (Multi-functionality)

Solution Approach 2:

The system uses reverse flow (opposite direction) to achieve cleaning function. By inverting the normal flow direction periodically, the system dislodges and removes accumulated particulate matter from the filter channels, maintaining filtration efficiency and extending operational life without requiring complex additional cleaning mechanisms.

Inventive Principle:
Principle #13The other way round (Inversion)

3Productivity

If continuous filtration is performed, then productivity is maintained, but particles accumulate in the filter channels, reducing reliability

Engineering Contradiction:
Improvefiltration outputVSAvoidfiltration performance
Core Design Contradiction:
ProductivityVSReliability

Solution Approach 1:

The system maintains continuous filtration productivity by automatically performing reverse flow cleaning during operation. The controller monitors flow conditions and initiates periodic reverse flow pulses to clear accumulating particles, ensuring that filtration performance and reliability are maintained without interrupting the overall continuous operation or requiring manual maintenance.

Inventive Principle:
Principle #20Continuity of useful action

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 system effectively cleans and maintains the filter channels, ensuring continuous and efficient filtration by repeatedly clogging and unclogging the channels, thereby extending the filter's operational life and maintaining high filtration performance.

Implementation Method 1

fluid in the second microfluidic channel fluid is pumped in a second direction opposite to the first direction

Methodology Applied
Scientific EffectReverse flow:

Implementation Method 2

a filtering channel (40) extending between and interconnecting the first microfluidic channel (24) and the second microfluidic channel (34)

Methodology Applied
Scientific EffectFiltration: Filter (physical)

Data Source

PatentEP3436176B1Microfluidic filtering system
Publication Date: 2020.04.15 HEWLETT PACKARD DEVELOPMENT COMPANY LP
  • EP3436176B1 patent drawingFigure 1~6
  • EP3436176B1 patent drawingFigure 7A~11
  • EP3436176B1 patent drawingFigure 12~14

AI summary

A microfluidic filtering system may include a first microfluidic channel, a first pump to move fluid along the first microfluidic channel in a first direction, a second microfluidic channel, a second pump to move fluid along the second microfluidic channel in a second direction opposite to the first direction and a filter channel extending between and interconnecting the first microfluidic channel and the second microfluidic channel.