Kamranikia Keynaz, Dominici Sébastien, Keller Marc, Kube Niklas, Mougin Karine, Spangenberg Arnaud
Institut de Science des Matériaux de Mulhouse (IS2M), CNRS-UMR 7361, Université de Haute-Alsace, 15 rue Jean Starcky, 68057 Mulhouse, France.
Université de Strasbourg, 67000 Strasbourg, France.
Micromachines (Basel). 2023 Aug 14;14(8):1602. doi: 10.3390/mi14081602.
Polymeric micropillars with a high-aspect-ratio (HAR) are of interest for a wide range of applications, including drug delivery and the micro-electro-mechanical field. While molding is the most common method for fabricating HAR microstructures, it is affected by challenges related to demolding the final structure. In this study, we present very HAR micropillars using two-photon polymerization (TPP), an established technique for creating complex 3D microstructures. Polymeric micropillars with HARs fabricated by TPP often shrink and collapse during the development process. This is due to the lack of mechanical stability of micropillars against capillary forces primarily acting during the fabrication process when the solvent evaporates. Here, we report different parameters that have been optimized to overcome the capillary force. These include surface modification of the substrate, fabrication parameters such as laser power, exposure time, the pitch distance between the pillars, and the length of the pillars. On account of adopting these techniques, we were able to fabricate micropillars with a very HAR up to 80.
具有高纵横比（HAR）的聚合物微柱在包括药物递送和微机电领域在内的广泛应用中备受关注。虽然模塑是制造高纵横比微结构最常用的方法，但它受到与最终结构脱模相关挑战的影响。在本研究中，我们使用双光子聚合（TPP）技术展示了非常高纵横比的微柱，TPP是一种用于创建复杂三维微结构的成熟技术。通过TPP制造的具有高纵横比的聚合物微柱在显影过程中经常会收缩和坍塌。这是由于微柱在制造过程中溶剂蒸发时主要作用的毛细管力作用下缺乏机械稳定性。在此，我们报告了为克服毛细管力而优化的不同参数。这些参数包括基板的表面改性、制造参数，如激光功率、曝光时间、柱之间的间距以及柱的长度。由于采用了这些技术，我们能够制造出纵横比高达80的非常高纵横比的微柱。
