Excellent chemical and physical properties of glass, over a range of operating conditions, make it a preferred material for chemical detection systems in analytical chemistry, biology, and the environmental sciences. However, it is often compromised with SU8, PDMS, or Parylene materials due to the sophisticated mask preparation requirements for wet etching of glass. Here, we report our efforts toward developing a photolithography-free laser-patterned hydrofluoric acid-resistant chromium-polyimide tape mask for rapid prototyping of microfluidic systems in glass. The patterns are defined in masking layer with a diode-pumped solid-state laser. Minimum feature size is limited to the diameter of the laser beam, 30 μm; minimum spacing between features is limited by the thermal shrinkage and adhesive contact of the polyimide tape to 40 μm. The patterned glass substrates are etched in 49% hydrofluoric acid at ambient temperature with soft agitation (in time increments, up to 60 min duration). In spite of the simplicity, our method demonstrates comparable results to the other current more sophisticated masking methods in terms of the etched depth (up to 300 μm in borosilicate glass), feature under etch ratio in isotropic etch (~1.36), and low mask hole density. The method demonstrates high yield and reliability. To our knowledge, this method is the first proposed technique for rapid prototyping of microfluidic systems in glass with such high performance parameters. The proposed method of fabrication can potentially be implemented in research institutions without access to a standard clean-room facility.

中文翻译：

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用于快速制造玻璃微流体系统的无光刻激光图案化 HF 耐酸铬聚酰亚胺掩模

玻璃在一系列操作条件下的优异化学和物理特性使其成为分析化学、生物学和环境科学中化学检测系统的首选材料。然而，由于玻璃湿法蚀刻的复杂掩模准备要求，它经常与 SU8、PDMS 或聚对二甲苯材料妥协。在这里，我们报告了我们在开发无光刻的激光图案化耐氢氟酸铬聚酰亚胺胶带掩模方面所做的努力，用于玻璃微流体系统的快速原型制作。这些图案是用二极管泵浦固态激光器在掩蔽层中定义的。最小特征尺寸受限于激光束的直径，30 μm；特征之间的最小间距受聚酰亚胺胶带的热收缩和粘合剂接触限制为 40 μm。带图案的玻璃基板在环境温度下在 49% 氢氟酸中蚀刻，同时轻轻搅拌（以时间为增量，持续时间长达 60 分钟）。尽管很简单，但我们的方法在蚀刻深度（硼硅玻璃中高达 300 μm）、各向同性蚀刻中的蚀刻比率（~1.36）和低掩模方面表现出与其他当前更复杂的掩模方法相当的结果孔密度。该方法展示了高产量和可靠性。据我们所知，这种方法是第一个提出的具有如此高性能参数的玻璃微流体系统快速原型技术。所提出的制造方法有可能在研究机构中实施，而无需使用标准的洁净室设施。