Owusu-Ansah Ebenezer, Dalton Colin
Department of Electrical & Computer Engineering, Schulich School of Engineering, University of Calgary, 2500 University Drive NW, Calgary, AB T2N 1N4, Canada.
Micromachines (Basel). 2020 Dec 6;11(12):1082. doi: 10.3390/mi11121082.
Micromodels are ideal candidates for microfluidic transport investigations, and they have been used for many applications, including oil recovery and carbon dioxide storage. Conventional fabrication methods (e.g., photolithography and chemical etching) are beset with many issues, such as multiple wet processing steps and isotropic etching profiles, making them unsuitable to fabricate complex, multi-depth features. Here, we report a simpler approach, femtosecond laser material processing (FLMP), to fabricate a 3D reservoir micromodel featuring 4 different depths-35, 70, 140, and 280 µm, over a large surface area (20 mm × 15 mm) in a borosilicate glass substrate. The dependence of etch depth on major processing parameters of FLMP, i.e., average laser fluence (LFav), and computer numerically controlled (CNC) processing speed (PSCNC), was studied. A linear etch depth dependence on LFav was determined while a three-phase exponential decay dependence was obtained for PSCNC. The accuracy of the method was investigated by using the etch depth dependence on PSCNC relation as a model to predict input parameters required to machine the micromodel. This study shows the capability and robustness of FLMP to machine 3D multi-depth features that will be essential for the development, control, and fabrication of complex microfluidic geometries.
微模型是微流体传输研究的理想选择，并且已被用于许多应用，包括石油开采和二氧化碳封存。传统制造方法（例如光刻和化学蚀刻）存在许多问题，如多个湿法处理步骤和各向同性蚀刻轮廓，这使得它们不适用于制造复杂的、具有多个深度的特征。在此，我们报告一种更简单的方法，即飞秒激光材料加工（FLMP），用于在硼硅酸盐玻璃基板上的大面积（20 mm×15 mm）上制造具有4种不同深度——35、70、140和280 µm的三维储层微模型。研究了蚀刻深度对FLMP主要加工参数的依赖性，即平均激光能量密度（LFav）和计算机数控（CNC）加工速度（PSCNC）。确定了蚀刻深度与LFav呈线性关系，而对于PSCNC则获得了三相指数衰减关系。通过将蚀刻深度与PSCNC关系的依赖性用作模型来预测加工微模型所需的输入参数，研究了该方法的准确性。这项研究展示了FLMP加工三维多深度特征的能力和稳健性，这对于复杂微流体几何形状的开发、控制和制造至关重要。
