3D printing cross-scale mold for manufacturing micromixers

Nowadays, the methods of manufacturing microfluidic mixers were not flexible enough to customize and manufacture special sizes. Hence, a novel electrohydrodynamic jet printing method was proposed to fabricate cross-scale mold for manufacturing micromixers in one step. Polyvinylpyrrolidone (PVP)/polycaprolactone (PCL) composite ink was prepared, and various printing parameters were investigated for fabricating varieties of 2D structures and 3D regular molds. A cross-scale spiral mixer was successfully printed, various diameter ratio of 5.6, aspect ratio of 7.2. The PVP/PCL lines were direct printed, size of 66 nm deep and 743 nm wide. The circles were size of 564 nm deep and 7.02 mu m wide. The mixing conditions of micromixers with different width ratios were simulated and analyzed; and the better mixing effect of micromixers with width ratio of 2:1 was proved, improved the mixing efficiency by 15.6% compared with micromixer without cross-scale channels. The cross-scale micromixers are promising for skin chip sensor and drug metabolite analysis, and the printing method proposed in this paper has great application potential in micro-electro-mechanical systems (MEMS).