In the lithography-based fabrication process of microstructures on microfluidic chip molds, the shortcoming of limited substrate materials seriously shortens the service lifetime of the mold. This research focuses on a profile shaping and surface finishing process of micro electrochemical machining (ECM) for microstructures with targeted dimensional and geometrical characteristics on the mold steel S136H. The effects of parameters on the material removal region and single-layer depth are firstly investigated. The sidewall taper of the machined groove increases with the machining voltage and decreases with the scanning velocity. Besides, the bottom surface quality is improved with increasing path spans. Then, the mathematical models of the material removal region and single-layer depth are analyzed, which are regarded as guidance for path planning and parameter optimization. In ECM experiments, a relatively higher machining voltage (20 V) is utilized to rapidly machine basic profiles of the designed flow resistor in the profiles shaping procedure. Sloping sidewalls and rough surfaces are finished by using a lower machining voltage (14 V) and a higher scanning velocity (500 μm s⁻¹) in the surface finishing procedure. As a result, the specially designed flow resistor with a dimensional deviation < 10 μm, and surface roughness R_a < 500 nm is obtained. The proposed ECM process is proved to machine microstructures with high precision and curve profiles on the mold steel.

在微流控芯片模具上基于光刻的微结构制造过程中，有限的基材材料的缺点严重缩短了模具的使用寿命。这项研究的重点是在模具钢S136H上具有目标尺寸和几何特性的微结构的微电化学加工（ECM）的轮廓成形和表面精加工工艺。首先研究了参数对材料去除区域和单层深度的影响。加工槽的侧壁锥度随加工电压而增加，随扫描速度而减小。此外，底面质量随路径跨度的增加而提高。然后，分析了材料去除区域和单层深度的数学模型，被视为路径规划和参数优化的指南。在ECM实验中，利用相对较高的加工电压（20 V）在轮廓成形过程中快速加工所设计的流量电阻器的基本轮廓。通过使用较低的加工电压（14 V）和较高的扫描速度（500μms）来完成倾斜的侧壁和粗糙表面^-1）在表面处理过程中。其结果是，特别设计的流阻器与一个尺寸偏差<10微米，表面粗糙度ř_一个<获得500纳米。实践证明，提出的ECM工艺可在模具钢上加工具有高精度和曲线轮廓的微结构。