Predictable Three-Dimensional Microfluidic Channel Fabrication in a Single-Mask Process

This paper presents the results of an investigation into the effect of geometrical patterns of the photomask on the dimensions of the trench that evolves after silicon isotropic etching. The study is based on the most complex surface pattern to date, composed of five independent geometric variables. Data from over 180 different patterns was collected to examine the influence of each parameter on the result. Two Langmuir-based models were developed relating the channel depth and width dimensions to the exposed pattern. These new models provide the capability to design complex microfluidic networks using only a single mask with channel dimensions predicted to 5% of their actual value.