3D Printed Microfluidic Channel Casting Mold

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Solution Overview

Problem

Existing methods for fabricating channel components for microfluidic devices are complex, time-consuming, material-intensive, and non-reproducible, often resulting in large channel diameters that limit miniaturization and compromise watertight integrity, making them inefficient and expensive for series production.

Innovation Solution

A method using 3D printing by photopolymerization to create an open mold with a UV hardenable resin core, allowing for the casting of polydimethylsiloxane channel components with fine structures and varied designs, enabling efficient, reproducible production of channel components with small diameters.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Ease of manufacture

If traditional soft lithography or Petri dish methods are used to fabricate channel components, then the fabrication process can be performed in the laboratory, but the process becomes complex, time-consuming, and non-reproducible

Engineering Contradiction:
Improvefabrication process simplicityVSAvoidprocess complexity
Core Design Contradiction:
Ease of manufactureVSDevice complexity

Solution Approach 1:

The patent uses 3D printing to create a digital model (STL file) that can be repeatedly copied to produce identical mold and core structures. This digital copying approach eliminates the need for manual fabrication of each component, ensuring high reproducibility while simplifying the manufacturing process. The same digital model can generate unlimited identical channel components without variation.

Inventive Principle:
Principle #26Copying

Solution Approach 2:

The patent changes the manufacturing parameters by transitioning from traditional soft lithography to 3D printing with photopolymerization. This parameter change enables precise control over channel dimensions (50-500 μm), allows for complex geometries including gradients and variations, and significantly reduces fabrication time while improving reproducibility across multiple components.

Inventive Principle:
Principle #35Parameter changes

2Manufacturing precision

If tubes, hoses or capillaries are used as casting cores, then channel components can be fabricated, but the channel diameters become too large for microanalytical techniques

Engineering Contradiction:
Improvechannel diameter precisionVSAvoidminiaturization capability
Core Design Contradiction:
Manufacturing precisionVSAdaptability or versatility

Solution Approach 1:

The patent employs disposable cores made from inexpensive materials (metal wire, fibre, or 3D-printed resin) that are inserted into the mold, used for casting, and then removed. These cores are not reused but serve their purpose effectively for creating precise channels. The disposable nature allows for optimization of each core's dimensions without concern for reuse, enabling precise control over channel diameters suitable for microanalytical techniques.

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

Solution Approach 2:

The patent transitions from using pre-formed tubes and capillaries with fixed diameters to 3D-printed cores that can vary in diameter along their length and across different components. This dimensional freedom allows channels to have diameters specifically optimized for microanalytical techniques (50-500 μm), including gradient diameters and complex geometries that cannot be achieved with standard tubing.

Inventive Principle:
Principle #17Another dimension (Dimensionality change)

3Productivity

If multiple channel components are needed for experiments, then more components can be used, but the fabrication time increases significantly

Engineering Contradiction:
Improvefabrication efficiencyVSAvoidfabrication time
Core Design Contradiction:
ProductivityVSLoss of time

Solution Approach 1:

The patent performs preliminary action by creating a master digital model (STL file) that contains all the information needed for fabrication. This digital model can be repeatedly used to generate unlimited identical molds and cores without additional design time. The preliminary preparation of the digital model and master mold enables rapid production of multiple channel components, dramatically improving productivity while minimizing fabrication time for series production.

Inventive Principle:
Principle #10Preliminary action

4Ease of manufacture

If Petri dish modification or silicone foil cutting is performed, then molds can be created, but the preparatory steps become time-consuming and material-intensive

Engineering Contradiction:
Improvemold fabrication easeVSAvoidmaterial consumption
Core Design Contradiction:
Ease of manufactureVSLoss of substance

Solution Approach 1:

The patent replaces mechanical fabrication methods (cutting silicone foil, modifying Petri dishes with pliers and adhesives) with 3D printing technology. This substitution eliminates the need for manual cutting, shaping, and assembly steps. The 3D printing process directly creates the mold and core structures from digital models, reducing both time consumption and material waste while improving precision and reproducibility.

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

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 method simplifies and accelerates the fabrication process, reduces material and time costs, and ensures high reproducibility, allowing for the production of channel components with fine structures suitable for a wide range of analytical methods.

Implementation Method 1

3D printing by photopolymerization to create an open mold with a UV hardenable resin core

Methodology Applied
Scientific EffectPhotopolymerization: Photopolymerisation

Implementation Method 2

a heat-curable polymerization mixture containing polydimethylsiloxane is poured into the mold, which is subsequently hardened by applying elevated temperature

Methodology Applied
Scientific EffectHeat curing: Heating

Data Source

PatentEP4501455B1A method for casting a channel component for use in microfluidic devices and an open mold for casting a channel component
Publication Date: 2025.09.24 UNIV KARLOVA V PRAZE
  • EP4501455B1 patent drawingFigure 1~3
  • EP4501455B1 patent drawingFigure 4~6
  • EP4501455B1 patent drawingFigure 7~9

AI summary

The invention relates to a method for casting a channel component (1) for use in microfluidic devices, in which at least one core (3) is inserted into the open mold (2) for casting the channel (4), then heat-curable polydimethylsiloxane is poured into the mold (2), which is subsequently thermally hardened and then the core (3) is removed from the mold (2). The core of the present invention is that the mold (2) and the core (3) are prepared by 3D printing by photopolymerization as a single integral body (5) of UV hardenable resin, then washed, dried and hardened by UV radiation, and after pouring and hardening of polydimethylsiloxane, the walls (6) and the bottom (7) of the mold (2) are mechanically removed, and the core (3) is removed from the body (5) of the channel part (1) by pulling.