Design and Optimization of an Open Configuration Microfluidic Device for Clinical Diagnostics

Abstract

This paper addresses the design and optimization of an electrowetting chip to transport biosamples in microdroplets, for future integration in a microfluidic device for cancer diagnostics. Materials and chip configuration are optimized to obtain a sustainable system, requiring low voltage to transport the microdroplets. Within this scope, droplet dynamic behavior is accurately described and considered in the design of the chip. Hence, in a first approach, a basic chip configuration is designed, and experiments are performed to determine the basic size and positioning of the electrodes, as a function of droplets diameter and displacement velocity. Then these basic dimensions are used in a numerical model, to optimize the chip configuration (e.g. distance between electrodes, thickness of the dielectric). The model includes effects of droplet evaporation by mass diffusion, which are experimentally validated. Overall the results confirm the potential of this model as a design tool for effective chips.