Routing Performance Optimization for Homogeneous Droplets on MEDA-based Digital Microfluidic Biochips

Abstract

Digital Microfluidic based Biochips (DMFBs) are capable of automation, re-configurable, low operational cost and accuracy of results. Such Lab-on-Chips (Loc's) are now extensively used in point of care diagnosis and other monitoring applications. Routing of micro or nano (10^-6 or 10^-9) litre volume of droplets on such chips elevate few critical challenges due to the blockages caused by microfluidic modules present on the chip. Micro-Electrode Dot Array (MEDA) based architecture of DMFB can facilitate cross contamination free routing and eradicate other routing issues over conventional DMF chips. This paper proposes a novel heuristic routing technique for MEDA based DMFB architecture to tackle routing complexities due to overlapping nets, interfering blockages and deadlock zones formed by the conflicting nets. We have categorized various region based movements of droplet on MEDA chip and derived a metric named Snooping Index (SIn) to improve the routing performance of the droplets in first phase. Next an exhaustive search is applied to find the routing path for the remaining nets considering different constraints specific to MEDA platform. Finally we have computed another measure called 'Zone Compaction Factor' (ZCF) to overcome blockage extensive route paths. Experimental results on benchmark suite I and III show our proposed technique significantly reduces latest arrival time, average assay execution time and number of used cells as compared with earlier methods.