Three-dimensional coaxial multi-nozzle device for high-rate microsphere generation

To address the need for production of a large number of microspheres for use in various fields such as tissue engineering, we developed a 3D coaxial multi-nozzle flow focusing device fabricated via a simple 3D printing method that demonstrates a high rate of microsphere production per nozzle. This device has six coaxial microscale nozzles that produce hydrogel microspheres. Two individual parts—the inlet and nozzle—can be made separately by a 3D printer and bonded together using uncured photo-curable resin as glue. The dimensions of the microspheres are between 100 and 1200 μm. They are produced by adjusting the flow rate ratio between the dispersed and continuous media. A flow rate ratio of 180 demonstrated the highest microsphere production rate of 2.12e+5 microspheres per second (0.25 mL min⁻¹). This microsphere production rate per nozzle is four times higher than that of currently available devices.