3D Microstructure Fabrication via Immiscible Fluid Displacement

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Solution Overview

Problem

Existing methods for producing three-dimensional structures in microstructure technology and microfluidics face limitations, including insufficient resolution, surface roughness, and the inability to create complex, hollow, or closed channel structures with circular cross-sections, due to the discretization of components along the construction direction and the requirement for flat substrates.

Innovation Solution

A method involving the use of a first polymerizable fluid and a second non-polymerizable fluid, where the second fluid is introduced into the first fluid to create a three-dimensional structure, which is then polymerized to form a matrix, allowing for the production of complex, hollow, or closed structures with circular cross-sections by adjusting the specific densities of the fluids and using a controllable application system to precision-place the second fluid.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Manufacturing precision

If layer-by-layer additive manufacturing (stereolithography, 3D printing, fused deposition) is used to produce three-dimensional structures, then three-dimensional components can be created, but the resolution is insufficient and surface roughness is high due to discretization along the construction direction

Engineering Contradiction:
ImproveresolutionVSAvoidlayer-by-layer construction process
Core Design Contradiction:
Manufacturing precisionVSDevice complexity

Solution Approach 1:

Instead of building structures layer by layer from solid material, the invention inverts the approach by removing material (second fluid) from a continuous matrix (first fluid) to create hollow three-dimensional structures. This eliminates the discretization problem inherent in additive manufacturing and enables high-resolution microstructures with smooth surfaces.

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

Solution Approach 2:

The invention extracts the desired three-dimensional structure by removing the second fluid from specific locations within the first fluid matrix. This extraction process creates hollow channels and cavities with precise geometries, avoiding the surface roughness and discretization artifacts associated with layer-by-layer construction.

Inventive Principle:
Principle #2Taking out (Extraction)

2Shape

If soft lithography is used to produce microfluidic channel structures, then two-dimensional structures can be created, but complex three-dimensional structures with circular cross-sections cannot be achieved

Engineering Contradiction:
Improvecircular channel cross-sectionVSAvoidthree-dimensional structure complexity
Core Design Contradiction:
ShapeVSManufacturing precision

Solution Approach 1:

The invention transitions from two-dimensional soft lithography to three-dimensional structure creation by enabling material removal and formation in all spatial dimensions. The controllable application system can deposit the second fluid at any (x, y, z) location, allowing complex three-dimensional hollow structures with circular cross-sections to be formed throughout the volume of the first fluid.

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

3Ease of manufacture

If the specific density difference between first and second fluids is large, then the second fluid can be easily removed, but the second fluid sinks or floats during the process affecting structure precision

Engineering Contradiction:
Improvesecond fluid removalVSAvoidstructure position accuracy
Core Design Contradiction:
Ease of manufactureVSManufacturing precision

Solution Approach 1:

The invention optimizes the density parameter by selecting fluid combinations with matched specific densities (differing by maximum 20%). This parameter matching prevents gravitational sinking or floating of the second fluid during processing, ensuring precise structural positioning while still allowing easy removal of the second fluid after polymerization through solvent extraction or other removal techniques.

Inventive Principle:
Principle #35Parameter changes

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

This method enables the precise and simple production of complex interpenetrating, hollow, or closed micro and fine structures with circular or oval channel cross-sections, overcoming the limitations of existing technologies by allowing for high-resolution, finely structured microfluidic channel networks and reducing surface roughness.

Implementation Method 1

c) polymerizing the first fluid, thereby obtaining the polymeric matrix into which the three-dimensional structure is introduced

Methodology Applied
Scientific EffectPolymerization: Photopolymerisation

Implementation Method 2

the first fluid having a first specific density and the second fluid having a second specific density, the first specific density and the second specific density differing from each other by a maximum of 20%

Methodology Applied
Scientific EffectDensity difference separation: Density Gradient

Data Source

PatentEP3305495B1Method for generating a three-dimensional structure in a matrix
Publication Date: 2023.05.03 KARLSRUHER INST FUR TECH
  • EP3305495B1 patent drawingFigure 1a~1b
  • EP3305495B1 patent drawingFigure 2A~3
  • EP3305495B1 patent drawingFigure 4~6D

AI summary

The invention relates to a method for producing a three-dimensional structure (112) in a matrix (114). The method comprises the following steps: a) providing a first polymerizable fluid (128) in a vessel (126); b) introducing a second non-polymerizable fluid (132) by means of a controllable application system (136) to at least one selected location (134) within the first fluid (128), wherein the first fluid (128) and the second fluid (132) are immiscible, thereby creating the three-dimensional structure (112); and c) polymerizing the first fluid (128), thereby obtaining the matrix (114) into which the three-dimensional structure (112) is introduced.The present method can be used in particular for the simple and precise fabrication of simple or complex interpenetrating, hollow, open or closed three-dimensional structures (112) in the field of microstructure technology and microfluidics.