Red blood cells separation in a curved T-shaped microchannel fabricated by a micromilling technique

Biomedical microfluidic devices are fabricated using different fabrication technologies. The most popular method is the soft-lithography manly due their main attraction, its high resolution capabilities and low material cost. However, usually, the fabrication of the moulds to produce microfluidic devices, is performed in a cleanroom environment and with specialized equipment that can be quite time consuming and costly. The micromilling is an alternative process that demonstrated potential to address some of the challenges in microdevices fabrication. It is a precise method, capable of creating complex channel geometries with specific measurements while ensuring a high level of resolution and a small error of tolerance, at the micron scale level. In fact, the non-necessity of a clean room, and being a fast and cheap manufacturing method makes it a great alternative to the traditional lithography process. Thus, in the present work, we show the ability of a micromilling machine to manufacture complex microchannels such as a curved T-shaped microchannel. By using a high-speed microscopic video system, flow visualizations and measurements were performed at four separation regions. Overall, the results show that the curved T-shaped microchannel is able to perform partial separation of blood cells from plasma.This work was supported by Fundação para a Ciência e a Tecnologia (FCT) under the strategic grants UID/EEA/04436/2019, UID/EMS/04077/2019, and UID/EMS/00532/2019. The authors are also grateful for the funding of FCT through the projects POCI-01-0145-FEDER-016861, NORTE-01-0145-FEDER-029394, NORTE-01-0145-FEDER-030171, funded by COMPETE2020, NORTE2020, PORTUGAL2020, and FEDER, and the PhD grant SFRH/BD/91192/2012