Fig. 3: Single-cell trapping mechanism and flow parameters using simulation model.

In this design, each of the sixteen microfluidic channels is integrated with pillar-like traps for trapping of single cells on microfluidic chip. A, B Regardless of whether single cells (A) or multiple cells (B) are injected at the entrance of the microfluidic channel, simulation model in ANSYS Fluent demonstrated that the cells need to be at the center of the channel to physically interact with the pillars and be isolated. C Flow profile in the channel, when a particle of 15 µm is trapped by the pillars. From the flow profile it can be predicted that when other cells enter the channel, they are diverted to the sides of the pillar by virtue of flow profile as there is almost little to no flow through the 4 µm gap between the pillars. D Once a cell or a particle has been physically trapped by the PDMS pillars, they will be subjected to shear stress, ranging between 0.25 Pa and 2 Pa, from the flow in the channels. (The white space in the particle, that can be seen as hole, is the part of the section that attaches with the trap during assembly. Upon hiding the traps, that specific section in the rigid particles also disappears giving the impression of hole. This section is not affected by the flow, according to the simulation software.) The particle dimension in this simulation model is 15 µm and the flow rate is 1 µL/min.