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Very High-Aspect-Ratio Polymeric Micropillars Made by Two-Photon Polymerization.
Keynaz Kamranikia1,2, Sébastien Dominici1,2, Marc Keller1,2
1Institut de Science des Matériaux de Mulhouse (IS2M), CNRS-UMR 7361, Université de Haute-Alsace, 15 rue Jean Starcky, 68057 Mulhouse, France.
Micromachines
|August 26, 2023
Summary
Researchers developed high-aspect-ratio (HAR) polymeric micropillars using two-photon polymerization (TPP). Optimized fabrication parameters successfully overcame capillary forces, preventing collapse and achieving HARs up to 80.
Area of Science:
- Materials Science
- Microfabrication
- Polymer Chemistry
Background:
- High-aspect-ratio (HAR) polymeric micropillars are crucial for applications like drug delivery and micro-electro-mechanical systems (MEMS).
- Conventional molding techniques face challenges with demolding complex HAR microstructures.
- Two-photon polymerization (TPP) is a versatile method for 3D microfabrication but struggles with micropillar collapse due to capillary forces during development.
Purpose of the Study:
- To present a method for fabricating very high-aspect-ratio (HAR) polymeric micropillars using two-photon polymerization (TPP).
- To overcome the common issue of micropillar shrinkage and collapse caused by capillary forces during the TPP fabrication process.
Main Methods:
- Utilized two-photon polymerization (TPP) for fabricating polymeric micropillars.
- Optimized substrate surface modification to enhance adhesion and reduce capillary effects.
- Adjusted TPP fabrication parameters including laser power, exposure time, and pitch distance between pillars.
- Investigated the influence of pillar length on structural integrity.
Main Results:
- Successfully fabricated polymeric micropillars with very high aspect ratios (HAR) up to 80.
- Demonstrated effective mitigation of capillary forces through optimized fabrication parameters and surface treatments.
- Achieved stable, non-collapsed micropillar structures previously unattainable with standard TPP methods.
Conclusions:
- Two-photon polymerization (TPP) can be optimized to produce ultra-high-aspect-ratio (HAR) polymeric micropillars.
- Careful control over fabrication parameters and surface conditions is essential to overcome capillary-induced collapse.
- This advancement enables the reliable fabrication of HAR microstructures for advanced applications.
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