Design and simulation of a hybrid deterministic lateral displacement and dielectrophoretic micro-device for bacterial separation from blood cells

Bacterial infections are a leading cause of mortality globally, and the timeliness of diagnosis is crucial for effective treatment. Traditional diagnostic methods, reliant on bacterial cultures, are often slow, leading to delays in treatment and increased mortality rates. To address delayed treatments, the study proposes a hybrid microfluidic device that employs deterministic lateral displacement (DLD) and dielectrophoresis (DEP) for rapid and continuous bacterial separation from blood cells. The research utilized COMSOL Multiphysics 5.6 to design and simulate the device, focusing on the optimization of various parameters such as pillar geometry, electrode geometry, fluid velocity, voltage, and DEP frequency. In order to calculate the separation efficiency, 120 particles along with the fluid were entered into the primary initial and the optimized hybrid device. The initial simulations yielded a separation efficiency of approximately 72% for bacteria and red blood cells (RBCs), and 100% for white blood cells (WBCs). After iterative optimization of the device’s design, including changes to the pillar geometries and electrode geometries and numbers, the separation efficiency for bacteria and RBCs was enhanced to 95%, while the efficiency for WBCs remained at 100%. These findings demonstrate the high efficiency of the designed microfluidic device in separating particles, indicating its potential to significantly reduce the time required for the detection of bacterial infections compared to conventional methods. The study presents a model of a microfluidic device that not only accelerates the diagnosis process but also maintains high separation efficiency, making it a promising tool for rapid point-of-care diagnostics.