Fabrication of a Metal Master Mold for Microfluidic Chips Using Laser Ablation

The fabrication of microfluidic chips using the laser ablation method is a promising alternative to the traditional photolithography technique. However, a non-optimal selection of laser parameters during surface processing can lead to low quality or damage of the substrate. Therefore, there is a relevant need for a systematic investigation of the influence of laser processing parameters on the resulting characteristics of the substrate’s microrelief. This work examines the specifics of manufacturing a metallic master mold for microfluidic chips via laser ablation. The methodological aspects of the master mold fabrication process are discussed in detail, particularly those related to the selection of optimal laser parameters and the choice of master mold material. It is shown that the maximum resolution of microstructures and channels on stainless steel is achieved at a laser power of 0.6 W and a frequency of 40 kHz. A linear dependence of channel depth on the number of laser passes was established: 0.5 μm per pass at a speed of 400 mm/s. For aluminum, the optimal power and frequency parameters were 3 W and 30 kHz, respectively. However, no material removal from the substrate surface occurred under these conditions, rendering aluminum a suboptimal choice for master mold fabrication. Thus, the feasibility of using the laser ablation method to manufacture metal master molds for microfluidic chips was demonstrated. Despite a number of identified limitations related to resolution and the need to tailor laser parameters for each material type, this method is promising for the rapid prototyping of microfluidic devices.