Numerical modelling and simulation of a lab-on-a-chip for blood cells’ optical analysis

Abstract

Blood is a treasure of information about the functioning of the whole body. Thus, there is a continuous need for new, accurate, fast, and precise techniques to analyse blood samples. The goal of this work is to design and numerically simulate a low-cost lab-on-a-chip device, which, in the future, can be used to quickly diagnose diseases by using a tiny drop of a blood sample from the patient. The designed microdevice includes two fluid inlets, a serpentine area for achieving a continuous and fully developed flow, as well as a detection chamber able for optical measurements. The numerical model of the designed microdevice was computed using COMSOL Multiphysics software, taking into account the flow and tracking of microparticles, mimicking blood cells. In order to reach the best lab-on-a-chip geometry, i.e., achieving a high and stable number of particles in the detection chamber during the entire microfluidic assay, the inlet velocity, the channel width, and the diameter of the detec tion chamber were individually optimized. A mesh study was also performed to achieve the best results’ accuracy, with lowest computational effort. From the achieved results, it was observed that a lab-on-a-chip geometry with a 0.5 mm channel width and a 2- or 3-mm detection chamber radius, with a fluid inlet velocity of 3 mm/s, was the one with the most interesting results for the intended application, with a constant number of particles flowing through the detection chamber (142 in average, for the selected inlet conditions).