Microparticle Fabrication by Degassed Molds and Discontinuous Dewetting
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Solution Overview
Problem
Conventional methods for fabricating microparticles face challenges in loading and isolating precursors in microwells, limiting productivity and polymerization mechanisms, and are restricted to specific polymer compositions and polymerization types.
Innovation Solution
A method utilizing the suction force of a degassed porous micromold to load a precursor and employing discontinuous dewetting to isolate the precursor in microwells, enabling the synthesis of microparticles with uniform shape and size, allowing for mass production and various chemical reactions.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of manufacture
If replica molding is used to fabricate microparticles, then anisotropic microparticles can be produced with simple and economical techniques, but loading of the precursor into the micrawells and isolation of the precursor filled in the micrawells are technically difficult to achieve
Solution Approach 1:
The invention changes the surface energy parameter of the mold material by using materials with inherently low surface energy (fluorinated polymers) or applying low surface energy coatings. This parameter change enables the precursor to be easily isolated from the microwells through dewetting, resolving the operational difficulty while maintaining the simplicity of the replica molding technique
Solution Approach 2:
The invention introduces an intermediary substance (oil layer) between the precursor and the environment during the isolation process. This intermediary facilitates the dewetting process by providing a compatible interface that allows the precursor to detach from the microwells cleanly, solving the isolation difficulty without complicating the overall manufacturing process
2Reliability
If PRINT method is used with fluorinated polymers for the mold and cover, then the precursor can be isolated from micrawells, but the fluorinated polymers are expensive and the surface energy of the precursor should be higher than that of the mold
Solution Approach 1:
The invention makes the mold surface universally compatible with various precursor types by using materials or coatings with low surface energy. This universal low-energy surface works with precursors having different surface energies, allowing the same mold system to be used for diverse applications without requiring precursor surface energy to exceed mold surface energy
Solution Approach 2:
The invention offers the option of using inexpensive elastomeric molds with applied low surface energy coatings instead of expensive fluorinated polymer molds. The coating can be applied to standard molds, making the system more accessible and versatile while maintaining the reliable isolation capability
3Productivity
If free-radical polymerization is used, then microparticles can be synthesized, but only microparticles composed of synthetic polymer can be produced and a thin precursor layer region is not formed by polymerization due to oxygen inhibition
Solution Approach 1:
The invention creates an inert environment by immersing the mold-precursor system in an oil layer that excludes oxygen from the precursor. This oxygen-free environment enables various polymerization mechanisms (free-radical, addition, thermosetting) to proceed effectively, resolving the limitation to only synthetic polymers while maintaining high productivity through complete polymerization of the precursor layer
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 the production of uniform microparticles with diverse compositions and shapes through free-radical polymerization, addition reactions, and thermosetting, while allowing for large-scale production and preventing precursor evaporation.
Implementation Method 1
utilizing the suction force of a degassed porous micromold to load a precursor
Implementation Method 2
employing discontinuous dewetting to isolate the precursor in micrawells
Implementation Method 3
curing the microparticle precursor solution filled in the micrawells to synthesize microparticles
Implementation Method 4
synthesis of microparticles with diverse compositions and shapes through free-radical polymerization, addition reactions, and thermosetting
Implementation Method 5
synthesis of microparticles with diverse compositions and shapes through free-radical polymerization, addition reactions, and thermosetting
Data Source
AI summary
The present invention relates to a method for fabricating microparticles by using a degassed gas-permeable micro-mold and discontinuous dewetting. The method for fabricating microparticles according to the present invention comprises the steps of: depressurizing and degassing a porous micro-mold including a plurality of micro-wells concavely recessed in a predetermined shape and size from one surface thereof (S100); loading a microparticle precursor solution on which the micro-wells are formed, and covering the microparticle precursor solution with a cover substrate (S200); moving the cover substrate to the side (S300); and curing the microparticle precursor solution filled in the micro-wells, thereby synthesizing microparticles (S400).