Microfluidic Chip Interface for Automated Fluid Handling

Resolve Bottlenecks,
Find Innovative Solutions
Generate Solutions

Solution Overview

Problem

Automated capillary electrophoresis for sample analysis is hindered by difficulties in handling and delivering small fluid volumes to microfluidic chips, and manual fluid transfer leads to inefficiencies and contamination on the chip surface, disrupting fluid flow and electrical measurements.

Innovation Solution

A fluidic and electrical interface system that includes a microchip tray, electrical bus, fluid manifold assembly with pumps, and precise dispensing and aspiration tubes to manage fluid flow and electrical connections, ensuring fluid is directed within the chip without spilling and maintaining electrical integrity.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Ease of operation

If manual fluid transfer is used to introduce samples into the microchip, then fluid handling is simple, but fluid spills and contamination on the chip surface occur, disrupting fluid flow and electrical measurements

Engineering Contradiction:
Improvefluid handling simplicityVSAvoidmeasurement accuracy
Core Design Contradiction:
Ease of operationVSReliability

Solution Approach 1:

The patent introduces an intermediary fluid delivery system consisting of a micropipette mounted on a positioning stage that precisely delivers fluid to the chip's reservoir. This intermediary mechanism bridges the gap between manual handling and automated precision, eliminating spills while maintaining operational simplicity through the use of a controllable micropipette system with x-y-z positioning capability.

Inventive Principle:
Principle #24Intermediary (Mediator)

Solution Approach 2:

The patent replaces manual mechanical fluid transfer with an automated micropipette positioning system controlled by motors or piezoelectric actuators. This substitution eliminates human error in fluid delivery while maintaining the simplicity of the fluid handling process through automated control, thereby improving measurement reliability without sacrificing ease of operation.

Inventive Principle:
Principle #28Mechanics substitution (Replace mechanical system)

2Productivity

If electrical probes are used to apply voltage to the channels, then electrophoretic flow is induced, but electrical contact stability is difficult to maintain

Engineering Contradiction:
Improveelectrophoresis efficiencyVSAvoidelectrical contact stability
Core Design Contradiction:
ProductivityVSReliability

Solution Approach 1:

The patent implements preliminary action by providing spring-loaded electrical contacts that are pre-positioned and spring-loaded to maintain constant pressure against the chip's electrical terminals. This preliminary setup ensures stable electrical contact is established before electrophoresis begins, eliminating contact instability during the process while maintaining high electrophoresis efficiency through reliable voltage delivery.

Inventive Principle:
Principle #10Preliminary action

3Manufacturing precision

If automated fluid delivery is implemented, then fluid handling precision is improved, but device complexity increases

Engineering Contradiction:
Improvefluid delivery precisionVSAvoidinterface complexity
Core Design Contradiction:
Manufacturing precisionVSDevice complexity

Solution Approach 1:

The patent applies segmentation by dividing the automated fluid delivery system into modular components: a micropipette module, a positioning stage with x-y-z control, and a control system. This segmentation allows each component to be optimized independently and simplifies the overall interface design, achieving high fluid delivery precision without excessive system complexity through modular architecture.

Inventive Principle:
Principle #1Segmentation

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 reliably and reproducibly transfers fluids and establishes electrical contact, preventing surface contamination and enabling precise fluid handling and analysis, enhancing the accuracy of capillary electrophoresis by maintaining fluid flow paths and electrical measurements.

Implementation Method 1

an electrolyte pump for filling and flushing wells with background electrolyte from source; a sample pump for filing and flushing fluid well with sample solution from source

Methodology Applied
Scientific EffectPump pressure: Pump

Implementation Method 2

a vacuum pump for aspirating the wells

Methodology Applied
Scientific EffectVacuum aspiration: Vacuum

Implementation Method 3

these fluids flow through a network of channels by capillary action, external pressure or electro-osmotic flow

Methodology Applied
Scientific EffectCapillary action: Capillary Action

Implementation Method 4

Voltages between a few hundred volts and greater than one thousand volts may be applied to the channels using electrical probes, for inducing electrophoretic and/or electro-osmotic flow useful for introducing small amounts of the sample fluid into the carrier channel

Methodology Applied
Scientific EffectElectro-osmotic flow: Electro-Osmotic Flow

Implementation Method 5

charged substances in the sample will separate in the carrier channel as a consequence of differences in electrophoretic mobility

Methodology Applied
Scientific EffectElectrophoresis: Electrophoresis

Data Source

PatentEP2780111B1Fluidic and electrical interface for microfluidic chips
Publication Date: 2019.08.28 METTLER TOLEDO THORNTON INC
  • EP2780111B1 patent drawingFigure 1A
  • EP2780111B1 patent drawingFigure 1B
  • EP2780111B1 patent drawingFigure 2

AI summary

Microfluidic chip interface for providing fluid communication with external fluid sources and external fluid waste containers, and for providing electrical contact with voltage sources and voltage and current measuring devices, is described. The microchip is first placed into electrical communication with at least one electrical source and at least one electronic measurement device, and reversibly secured in place. The fluid manifold is removed from fluid communication with the microchip during electrical measurements.