Effects of pillar shapes on the cell isolation in contactless DEP microfluidic devices

Contactless dielectrophoresis is an effective method for trapping and manipulating cells in microfluidic devices. However, the efficiency of these devices decreases at higher flow rates. To address the limitation of previous studies, a new pillar shape is introduced and numerically simulated to isolate THP-1 cells and efficiently separate them from red blood cells (RBCs). A comparison is made in two microchannels with the novel pillar shape of two perpendicular ellipses and the circular pillar shape as the reference case. Simulation results demonstrate that the use of two perpendicular ellipticals pillar shape improves the electric characteristics of the device, showing 92.7% higher \(\nabla {E}_{rms}^{2}\) $\mathrm{\nabla }{E}_{\mathit{rms}}^2$ compared to the channel with circular pillars. The working frequency is selected based on the CM factor to isolate THP-1 cells without affecting RBCs. Additionally, the new pillar configuration exhibited 116% higher cell trap efficiency compared to the chip with circular pillars.