Blood flow visualization and measurements in microfluidic devices fabricated by a micromilling technique

The most common and used technique to produce microfluidic devices for biomedical applications is the soft-lithography. However, this is a high cost and time-consuming technique. Recently, manufacturers were able to produce milling tools smaller than 100 μm and consequently have promoted the ability of the micromilling machines to fabricate microfluidic devices capable of performing cell separation. In this work, we show the ability of a micromilling machine to manufacture microchannels down to 30 μm and also the ability of a microfluidic device to perform partial separation of red blood cells from plasma. Flow visualization and measurements were performed by using a high-speed video microscopy system. Advantages and limitations of the micromilling fabrication process are also presented.The authors acknowledge the financial support provided by PTDC/SAU-ENB/116929/2010 and EXPL/EMS-SIS/ 2215/2013 from FCT (Science and Technology Foundation), COMPETE, QREN and European Union (FEDER). DP acknowledge the PhD scholarship SFRH/BD/89077/2012, and P.C. Sousa acknowledges the fellowship SFRH/BPD/75258/ 2010, all attributed by FCT.