Figure 2. Numerical modeling of fluid velocity, pressure, concentration profiles and shear stresses.

(A) Velocity profile of fluidic environment: Shows that the fluid velocity is highest in the region bridging the traps and lowest within the trap regions for an inlet flow rate of 50 μl/hr; heat map is in m/s. (B) Pressure drop across the device: The pressure doesn’t exceed 0.332 Pa, with the first trap experiencing the highest pressure at the inlet; heat map is in Pascals (Pa). (C) Time dependent concentration profile: Results from the convection-diffusion study for a molecule of standard diffusivity after 600 seconds of perfusion, shows that nearly half the chip has reached the inlet concentration; heat map is concentration (mol/m³). (D) Strain distribution in a hydrodynamic trap: The red lines display the cut lines where the shear stress was calculated for two different flow rates; heat map is strain rate (1/s). (E) Shear stress across the diameter of the trap: shows results for a flow rate of 50 μl/hr and 10 μl/min. (F) Shear stress across the high resistance channel: shows that higher shear stresses occur at the boundary between the trap and the suction channel for both flow rates of 50 μl/hr and 10 μl/min, but especially for the faster flow rate, demonstrating maximum shear stresses of 0.25 dynes/cm². These shear stresses are significantly below the threshold of 1.2 dynes/cm².