Automated path selection technique while incorporating multiple assay operations and cross-contamination avoidance in cross-referencing DMFBs

Abstract

Digital Microfluidic Biochips (DMFBs) perform many biochemical reactions requiring relatively less cost and very less amount of space. DMFBs that use cross-referencing addressing requires less number of pins, therefore, less manufacturing cost. However, it suffers from a problem called electrode interference, i.e., unwanted droplet operation because of an extra activated cell. DMFBs also suffer from a problem called cross-contamination, i.e., mixing of droplets with unwanted residues of droplets containing different chemicals which results in incorrect diagnosis. In this article, our objective is whether a cross-referencing DMFB with an efficient module placement design can be declared as a multifunctional chip or not. We propose a chip design which incorporates parallelism for enhancing performance in terms of assay completion time while performing multiple types of bioassays. We also propose a novel method, which automatically selects a new cross-contamination free path while routing from the source to the sink. We have included an on-chip washing scheme. The whole method ensures no Electrode Interference.