Fig. 2

a Complete binocular view of the microchip. Length = 4.6 mm, width = 3.3 mm b Enlarged SEM view of the chamber containing the trap array. The vertical and horizontal spacings of the traps are respectively 200 µm each. Scale = 500 µm. c Top and d tilted SEM view of a trap. The traps are U-shaped (inner length = 60 µm, inner width = 45 µm) and have 2 lateral and one backside (15 µm) openings to allow the medium to flow through the structure. The chamber height is set to 45 µm. Scale = 40 µm