Double Syringe for Microfluidic Fluid Supply

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Solution Overview

Problem

Conventional methods for supplying liquids to microfluidic systems are costly and impractical, especially for disposable cartridges, due to the use of expensive pumps with closable valves.

Innovation Solution

A double syringe design featuring concentric cylindrical chambers with axially movable pistons and annular seals, allowing for the efficient and cost-effective delivery of liquids into microfluidic systems, including the option for pre-filling and multi-liquid supply.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If conventional pumps with closable valves are used to supply liquids to microfluidic systems, then reliable liquid supply is achieved, but device cost and complexity increase significantly

Engineering Contradiction:
Improveliquid supply reliabilityVSAvoidpump and valve system complexity
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The pump chamber is segmented into multiple isolated compartments that can be independently activated. Each compartment can be controlled by its own valve, allowing selective activation of only the necessary compartments during operation. This segmentation reduces the overall complexity compared to a single large pump system while maintaining reliable liquid supply through distributed pumping capability.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The patent implements a nested structure where the piston is positioned within the pump chamber, and the valve mechanism is integrated into the pump body. The outlet conduit connects the inner piston area to the outer chamber. This nested arrangement consolidates multiple components into a compact integrated unit, reducing device complexity while preserving the reliable liquid supply function.

Inventive Principle:
Principle #7Nested doll (Nesting)

2Ease of manufacture

If disposable cartridges are used for microfluidic applications, then cost-effectiveness improves, but the ability to use expensive pumps with valves becomes impractical

Engineering Contradiction:
Improvedisposable cartridge cost-effectivenessVSAvoidliquid supply capability
Core Design Contradiction:
Ease of manufactureVSReliability

Solution Approach 1:

The patent designs a pump system specifically suited for disposable cartridges, eliminating the need for expensive reusable pumps with complex valve mechanisms. The pump chamber, piston, and integrated valve can be manufactured as single-use components using cost-effective methods, enabling disposable cartridges to maintain reliable liquid supply capability while being economically viable for single-use applications.

Inventive Principle:
Principle #27Cheap short-living objects (Disposable)

Solution Approach 2:

The valve mechanism is merged with the pump chamber structure, and the outlet conduit is integrated into the same component. This consolidation eliminates the need for separate valve assemblies and complex connections, making the entire liquid supply system manufacturable as a single disposable cartridge component, thereby improving cost-effectiveness while maintaining reliability.

Inventive Principle:
Principle #5Merging (Combining)

3Device complexity

If a simple syringe design is used for liquid supply, then device complexity decreases, but the ability to control fluid flow direction and manage multiple liquids is limited

Engineering Contradiction:
Improvesyringe structure simplicityVSAvoidfluid flow control capability
Core Design Contradiction:
Device complexityVSAdaptability or versatility

Solution Approach 1:

The patent employs a movable piston within the pump chamber that can be dynamically positioned to control fluid flow. The piston's movement creates pressure changes that direct fluid through the outlet conduit in a controlled manner. This dynamic element adds flow control capability to the otherwise simple syringe-like structure without significantly increasing complexity.

Inventive Principle:
Principle #15Dynamics

Solution Approach 2:

The pump chamber serves multiple functions: it acts as a reservoir for liquid, a pumping mechanism through piston movement, and a flow control valve through its integrated design. The outlet conduit serves both as an exit path and a sealing element. This multi-functionality allows the simple structure to handle multiple liquids and control flow directions without requiring additional specialized components.

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

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 double syringe provides a simple, reliable, and cost-effective means to supply and manage liquids within microfluidic systems, enhancing the efficiency and reliability of liquid handling in applications such as PCR and nucleic acid detection.

Implementation Method 1

by its movement towards the distal end, a liquid placed in the reservoir is forced through the through-bores into the inner chamber

Methodology Applied
Scientific EffectPressure differential: Pressure Gradient

Implementation Method 2

allows liquid to be drawn back from the microfluidic system into the inner chamber by an axial movement of the inner piston towards the proximal end

Methodology Applied
Scientific EffectSuction: Suction

Data Source

PatentEP3259064B1Double syringe for supplying a fluid into a microfluidic system
Publication Date: 2019.04.10 FRIZ BIOCHEM FUR BIOANALYTIK MBH
  • EP3259064B1 patent drawingFigure 1
  • EP3259064B1 patent drawingFigure 2~3
  • EP3259064B1 patent drawingFigure 4

AI summary

The invention relates to a double syringe (200) for supplying a fluid (202) into a microfluidic system comprising a cylindrical outer chamber (204) which defines a storage space (208) for receiving the fluid (202) to be supplied, a cylindrical inner chamber (206) arranged inside the outer chamber (204), which inner chamber in the distal cylinder cover area (212) thereof has an outlet opening (210) for connecting to the microfluidic system, and which has a fluidic connection to the outer chamber (204) via through-holes (218), an inner piston (216) which is axially displaceable in the inner chamber (206), which inner piston in a closed position closes the through-holes (218) on the inner chamber side and in a release position releases the through-holes (218) and enables a fluid flow from the outer chamber into the inner chamber, and an annular piston (214) which is displaceable in the outer chamber (204) axially to the distal end of the outer chamber, i) which in a proximal supply position closes off the storage space (208) for the fluid to be supplied, ii) through the displacement whereof to the distal end, a fluid (202) introduced in the storage space (208) is pressed via the through-holes (218) into the inner chamber (206) if the inner piston (216) is in the release position thereof, and iii) which in a distal closed position closes the through-holes (218) from the outer chamber side and hence enables a retraction of fluid from the microfluidic system into the inner chamber (206) by an axial movement of the inner piston (216) to the proximal end.