Microfluidic Fluid Dispenser for Variable-Volume Specimen Injection

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Solution Overview

Problem

Existing fluid injection systems struggle with handling highly variable volume sizes, particularly in the removal of small volumes, which is time-consuming and costly, and handling glass slides is challenging for robotic systems, leading to inefficiencies in specimen preparation for spatial omics experiments.

Innovation Solution

A fluid dispenser with a microfluidic mixing chamber and integrated fluid container system that allows precise mixing and application of fluids directly to a specimen, using pressurized fluid to facilitate mixing and temperature control to maintain reagent integrity, along with bubble and gas removal mechanisms to ensure accuracy and consistency.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Adaptability or versatility

If traditional dip and dunk method or pipetting is used for fluid injection, then the system is simple to operate, but it cannot handle highly variable volume sizes well and is time-consuming for small volume removal

Engineering Contradiction:
Improvehandling variable volume sizesVSAvoidtime-consuming small volume removal
Core Design Contradiction:
Adaptability or versatilityVSLoss of time

Solution Approach 1:

The patent replaces traditional mechanical pipetting and dip-and-dunk methods with a microfluidic injection system that uses pressure differentials and capillary forces to control fluid flow. This substitution enables precise handling of variable volumes without manual intervention, resolving the contradiction between adaptability to different volumes and time efficiency.

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

Solution Approach 2:

The system employs pneumatic pressure control through a pressure equalization chamber to regulate fluid injection into microfluidic channels. By controlling pressure differentials, the system can accurately deliver varying fluid volumes (from nanoliters to microliters) automatically, eliminating the time-consuming nature of traditional small volume handling while maintaining versatility.

Inventive Principle:
Principle #29Pneumatics and hydraulics

2Productivity

If manual handling of specimens is performed, then flexibility is maintained, but throughput is considerably reduced

Engineering Contradiction:
Improveexperimental throughputVSAvoidmanual handling flexibility
Core Design Contradiction:
ProductivityVSEase of operation

Solution Approach 1:

The microfluidic system is designed to automatically perform fluid injection, mixing, and specimen processing without manual intervention. The self-contained nature of the device, with integrated pressure control and fluid delivery mechanisms, enables high-throughput processing while maintaining operational simplicity through automated protocols.

Inventive Principle:
Principle #25Self-service

Solution Approach 2:

The patent combines multiple functions (fluid storage, pressure control, mixing, and injection) into a single integrated microfluidic device. This merging of functions eliminates the need for separate manual operations for each step, thereby increasing throughput while preserving ease of operation through a unified automated system.

Inventive Principle:
Principle #5Merging (Combining)

3Reliability

If repeated rinsing with excess wash buffer is used to remove small volumes, then complete removal is achieved, but fluid consumption and time increase

Engineering Contradiction:
Improvecomplete fluid removalVSAvoidexcess wash buffer consumption
Core Design Contradiction:
ReliabilityVSLoss of substance

Solution Approach 1:

The system replaces manual rinsing operations with automated microfluidic pressure control that precisely delivers and removes fluids. This substitution ensures complete fluid removal through controlled pressure differentials while minimizing wash buffer consumption by delivering only the necessary volumes, thereby resolving the contradiction between reliability of removal and substance loss.

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

4Productivity

If batch processing with metal frame holders is used, then processing capacity increases, but space requirements and device complexity increase

Engineering Contradiction:
Improvebatch processing capacityVSAvoidmetal frame holder system
Core Design Contradiction:
ProductivityVSDevice complexity

Solution Approach 1:

The system segments the batch processing function into individual microfluidic cartridges, each capable of independent operation. This segmentation allows for scalable processing capacity without requiring complex metal frame holders, as each cartridge is a self-contained unit that can be processed individually or in batches, thereby reducing overall device complexity while maintaining productivity.

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

Enables efficient, automated, and easy-to-use specimen preparation by ensuring precise fluid mixing and application, maintaining reagent integrity, and reducing contamination risks, thereby enhancing experimental throughput and reproducibility.

Implementation Method 1

The microfluidic mixing chamber is configured to mix fluids provided via the first and second inputs and to output the mixed fluids via the output

Methodology Applied
Scientific EffectDiffusion: Diffusion

Implementation Method 2

The microfluidic mixing chamber is configured to mix fluids provided via the first and second inputs

Methodology Applied
Scientific EffectConvection: Convection

Implementation Method 3

The pressure line is configured to be connected to a pressure port of the fluid container to provide the fluid container with the pressurized fluid for discharging the second fluid from the fluid container via the second port into the microfluidic mixing chamber. The pressurized fluid displaces the second fluid from the fluid container.

Methodology Applied
Scientific EffectPressure gradient: Pressure Gradient

Implementation Method 4

The fluid dispenser comprises a bubble trap configured to remove gas bubbles from the first fluid and/or the second fluid

Methodology Applied
Scientific EffectBuoyancy: Archimedes' Principle (Buoyancy)

Data Source

PatentEP4616948A1Fluid dispenser for supplying a fluid to a microfluidic system and fluid container
Publication Date: 2025.09.17 LEICA MICROSYSTEMS CMS GMBH
  • EP4616948A1 patent drawingFigure 1
  • EP4616948A1 patent drawingFigure 2
  • EP4616948A1 patent drawingFigure 3

AI summary

A fluid dispenser (100, 300, 400) is configured to supply a fluid to a microfluidic system (102) and comprises a sample carrier position (200) configured to receive a sample carrier (104). The sample carrier (104) is configured to receive a microscopic specimen (202) and comprises the microfluidic system (102) having an injection port (112) configured to receive fluids intended to interact with the microscopic specimen (202). The fluid dispenser (100, 300, 400) also comprises a microfluidic mixing chamber (120) having a first input (122), a second input (124), and an output (126). The microfluidic mixing chamber (120) is configured to mix fluids provided via the first and second inputs (122, 124) and to output (126) the mixed fluids via the output (126). The fluid dispenser (100, 300, 400) further comprises a first port (136) configured to receive a fluid line (134) for providing a first fluid to the first input (122) of the microfluidic mixing chamber (120), a second port (140) configured to receive a fluid container (138) containing a second fluid to be mixed with the first fluid, and to provide the second fluid to the second input (124) of the microfluidic mixing chamber (120), and an adapter (130) configured to connect the output (126) of the microfluidic mixing chamber (120) to the injection port (112) of the sample carrier (104).