Process chain for the mass production of polymeric microfluidic chips

The moulding process is a low-cost method for the mass production of microfluidic chips, rather than fabricating the chips one by one. The precision manufacturing of the mould is the key to the moulding process, which usually includes a combination of several machining processes. However, most of the current studies focus on a single process in microfluidic chip fabrication, which makes it difficult to optimise the fabrication process, resulting in low production efficiency and high energy consumption. Therefore, to realize the low cost and sustainable mass production of microfluidic chips, the process chain is developed in this paper. The process chain includes milling, precision ultrasonic vibration–assisted grinding, fluid jet polishing, and injection moulding. Parametric experiments regarding the key parameters of grinding, polishing, and injection moulding are conducted to obtain the optimization conditions. The form accuracy of the microchannel reaches 8.594 μm, and the roughness at the bottom surface of the microchannel is 0.027 μm. The experimental results demonstrate that the proposed process chain is effective and feasible for the mass production of microfluidic chips with high surface quality. It also provides some theoretical bases for the manufacturing of structured surfaces with nanometric surface roughness.