Fabrication of Micro-Channels in PMMA by Tip-Based Microfabrication Technique: Depth and Friction Analysis

In this paper, millimeter-scale straight parallel micro-channels were fabricated in PMMA (Polymethyl-methacrylate) using the tip-based micro-fabrication method. The dimensional characteristics (channel width, channel depth and pile-up height) of micro-channels were evaluated and the effects of normal load and speed on the micro-channel geometry and friction were examined. A logarithmic relationship between the normal load and micro-channel depth was identified. The experimental results indicate that the selection of the normal load is critical to achieve a desired micro-channel geometry using a single pass scratching. To machine a micro-channel with a finite depth in PMMA, the normal load must be higher than 4.5 N. Within the range of the tested normal loads, about 70% of the channel height was elastically recovered after a single pass, and pile-ups as high as 50–60% of the depth were observed along the micro-channel sides.