Abstract

Modelling and Characterisation of Droplet Generation, Trapping and Detection in Impedance-Based Cell Analytical Microfluidic System

Peter Furjes, Principal Scientist, Hungarian Academy of Sciences

Droplet based microfluidics have developing relevance in the field of Lab-on-a-Chip technology. In these multi-phase flow devices, the continuous sheath emulsion enables to generate, manipulate, mix, focus and separate encapsulated chemical reagents or biosamples as assay of living cells. Therefore cell-analytical and diagnostic procedures can be automatized on microscale, although the precise control and monitoring of droplet parameters and behaviour are essential for their reliable application. Accordingly this work focuses on design and characterisation of a hybrid polymer microfluidic system having integrated electrode system. The developed system is capable of creating, manipulating, trapping and monitoring droplets having precisely determined size fitted to general cell diameter. The influence of flow characteristics of two-phase microfluidic systems was analysed regarding the droplet generation, particle encapsulation and trapping processes. Droplets were dispersed in oil continuous phase with the requirement of precise size distribution to enable effective cell entrapment controlled by the applied flow parameters. Hydrodynamic behaviour of the microfluidic system was modelled by Finite Element Method (FEM) using COMSOL Multiphysics and compared to experimental results. The applicability of droplet based cell encapsulation and hydrodynamic trapping and the capability of impedance spectroscopy based droplet and cell detection were also characterised.