Simulation of Droplet Position Control in Digital Microfluidic Systems

Digital microfluidic systems (DMSs) are emerging with high potential to serve as true labs-on-a-chip (LOCs) systems for various chemical and biochemical analyses. Significant research efforts have been devoted toward the design and fabrication of improved LOC systems. Due to design, fabrication, and also runtime uncertainties, feedback control schemes must be incorporated to ensure reliability and accuracy of LOCs for practical use. This paper introduces the basics of the control analysis and design of the DMS, which is a relatively unexplored area in digital microfluidics. Based on the semi-empirical models of the droplet dynamic system, simulation results of the closed-loop position control of a droplet between two adjacent cells of a DMS are presented. The dynamic response is analyzed and discussed in relation to the operational parameters of a DMS.