Figure 2. Fabrication of digital cell counting device based on a CMOS sensor integrated with a microcavity array.

(a, b) Schematic diagrams of shadow-imaging platform. (a) Only the light transmitted through the microcavities positioned above the CMOS sensor is received at the sensor surface. (b) When cells are trapped on the microcavities, the light is attenuated by the trapped cells. (c, d) Schematics of the expected CMOS sensor images acquired before (c) and after cell entrapment (d).