由于非金属材料对长波红外激光有较强的吸收, CO2 激光常被用于制备PMMA微通道。激光光强呈高斯分布, 导致常规激光静态多程刻蚀法制备的微通道截面为三角形, 无法满足微流体芯片中的实际应用需求。提出了一种激光多程平移刻蚀法, 以首次刻蚀形成的热影响区(HAZ)为界限多程横向重叠平移刻蚀, 可以快速制备出理想梯形截面的高质量微通道。通过与CO2 激光静态多程刻蚀法在横截面、热影响区、表面粗糙度等方面的对比, 结果表明, CO2 激光多程平移刻蚀法制备的PMMA微通道热影响区更小、表面更光滑、横截面更实用。

As non-metallic materials have strong absorption of long-wave infrared laser, the CO2 laser is often used to prepare PMMA micro-channels. Due to the Gaussian distribution of the laser light intensity, the cross-section of the micro-channels prepared by the conventional method is triangular. This can′t meet the practical application requirements in the microfluidic chip. In this paper, a CO2 laser multi-path translational method was proposed, which used the HAZ formed by the first etching as a boundary multi-pass lateral overlap translation etching, so that high quality micro-channels with ideal trapezoid cross section can be quickly prepared. In addition, the micro-channel fabricated in this way is smoother and more practical compared with the static multi-pass method in cross-section, HAZ, surface roughness.