2.2 Innovative fabrication
PDMS was fabricated from SYLGARD 184 with a ratio of 10:1.5 (elastomer base: curing agent). The mixture was poured to and cured by moulding and thus obtaining a rectangular block of PDMS with dimensions of 50 x 25 x 2 mm.
Vinyl offers a fast manufacturing of microchips with different layouts. This feature allows us to test different variants for the same application and check which one has greater performance.
Mactac vinyl sheets of 75 µm thick were cut with a cutter Summa S Class in two different layouts (Fig. 1A). A first layout (B) contains a circular area (radius ~5 mm) that delimits the area where the cells will be seeded, and a second layout (A) that adds to the main circular area two smaller holes intended for inlet and outlet flow channels that facilitates microscopic biological network observation, while avoids a direct incidence of the flow on the adhered cells. Both layouts A and B include 4 circles around the main design as an alignment guide for the vinyl sheets to overlap and thus obtain the required thickness. The microfluidic device is robust enough to preserve the water tightness by itself without the need of external fittings.