Bhagat Ali Asgar S, Jothimuthu Preetha, Papautsky Ian
Department of Electrical and Computer Engineering, 814 Rhodes Hall, ML030, University of Cincinnati, Cincinnati, OH 45221, USA.
Lab Chip. 2007 Sep;7(9):1192-7. doi: 10.1039/b704946c. Epub 2007 Jun 22.
In this paper, we introduce a new and simple method of patterning polydimethylsiloxane (PDMS) directly using benzophenone as a photoinitiator. The photodefinable PDMS mixture (photoPDMS) is positive-acting and only sensitive to light below 365 nm, permitting processing under normal ambient light. Features of the order of 100 microm, which are sufficiently small for most microfluidic applications, were successfully fabricated using this novel process. A parametric study of process parameters was performed to optimize the fabrication. As a demonstration, microfluidic channels of varying dimensions were successfully fabricated using this process and experimentally characterized using fluorescence microscopy. To further demonstrate photoPDMS potential, thin (<30 microm) free-standing films with through patterns were fabricated and successfully used as shadow masks. The photoPDMS process completely eliminates the need for a master, permits processing under normal ambient light conditions, and makes fabrication fast and simple. This process for rapid prototyping of low-cost, disposable LOCs can be accomplished without cleanroom facilities and thus can be employed for a wide range of applications.
在本文中，我们介绍了一种全新且简单的方法，即直接使用二苯甲酮作为光引发剂对聚二甲基硅氧烷（PDMS）进行图案化处理。可光定义的PDMS混合物（光致PDMS）是正性作用的，且仅对波长低于365 nm的光敏感，这使得其能够在正常环境光下进行加工。利用这种新颖的工艺成功制造出了尺寸为100微米左右的特征结构，对于大多数微流控应用而言，这样的尺寸已足够小。对工艺参数进行了参数研究以优化制造过程。作为演示，使用该工艺成功制造出了不同尺寸的微流控通道，并通过荧光显微镜对其进行了实验表征。为了进一步展示光致PDMS的潜力，制造出了具有通孔图案的薄（<30微米）独立薄膜，并成功将其用作荫罩。光致PDMS工艺完全无需母版，允许在正常环境光条件下进行加工，并且使制造过程快速且简单。这种用于低成本、一次性微全分析系统快速原型制作的工艺无需洁净室设施即可完成，因此可用于广泛的应用。
