Pham Q L, Tong N A N, Mathew A, Basuray S, Voronov R S
Otto H. York Department of Chemical and Materials Engineering, New Jersey Institute of Technology, Newark, New Jersey 07102, USA.
Department of Biomedical Engineering, New Jersey Institute of Technology, Newark, New Jersey 07102, USA.
Biomicrofluidics. 2018 Aug 22;12(4):044119. doi: 10.1063/1.5035282. eCollection 2018 Jul.
A custom-built mask aligner (CBMA), which fundamentally covers all the key features of a commercial mask aligner, while being low cost and light weight and having low power consumption and high accuracy, is constructed. The CBMA is composed of a custom high fidelity light emitting diode light source, a vacuum chuck, a mask holder, high-precision translation and rotation stages, and high resolution digital microscopes. The total cost of the system is under $7500, which is over ten times cheaper than a comparable commercial system. It produces a collimated ultraviolet illumination of 1.8-2.0 mW cm over an area of a standard 4-in. wafer, at the plane of photoresist exposure, and the alignment accuracy is characterized to be <3 m, which is sufficient for most microfluidic applications. Moreover, this manuscript provides detailed descriptions of the procedures needed to fabricate multilayered master molds using our CBMA. Finally, the capabilities of the CBMA are demonstrated by fabricating two- and three-layer masters for micro-scale devices, commonly encountered in biomicrofluidic applications. The former is a flow-free chemical gradient generator, and the latter is an addressable microfluidic stencil. Scanning electron microscopy is used to confirm that the master molds contain the intended features of different heights.
构建了一种定制掩膜对准器（CBMA），它从根本上涵盖了商用掩膜对准器的所有关键特性，同时具有低成本、轻重量、低功耗和高精度的特点。CBMA由定制的高保真发光二极管光源、真空吸盘、掩膜夹具、高精度平移和旋转台以及高分辨率数字显微镜组成。该系统的总成本低于7500美元，比同类商用系统便宜十多倍。在光刻胶曝光平面上，它在标准4英寸晶圆的区域内产生1.8 - 2.0 mW/cm的准直紫外线照明，并且对准精度被表征为<3μm，这对于大多数微流体应用来说已经足够。此外，本文详细描述了使用我们的CBMA制造多层母模所需的步骤。最后，通过为生物微流体应用中常见的微尺度器件制造两层和三层母模，展示了CBMA的能力。前者是无流动化学梯度发生器，后者是可寻址微流体模板。使用扫描电子显微镜来确认母模包含不同高度的预期特征。
