Droplet-trace-based array partitioning and a pin assignment algorithm for the automated design of digital microfluidic biochips

Abstract

Microfluidics-based biochips combine electronics with biology to open new application areas such as point-of-care medical diagnostics, on-chip DNA analysis, and automated drug discovery. Bioassays are mapped to microfluidic arrays using synthesis tools, and they are executed through the manipulation of sample and reagent droplets by electrical means. Most prior work on CAD for biochips has assumed independent control of electrodes using a large number of (electrical) input pins. Such solutions are not feasible for low-cost disposable biochips that are envisaged for many field applications. A more promising design strategy is to divide the microfluidic array into smaller partitions and use a small number of electrodes to control the electrodes in each partition. We propose a partitioning algorithm based on the concept of "droplet trace", which is extracted from the scheduling and droplet routing results produced by a synthesis tool. An efficient pin assignment method, referred to as the "Connect-5 algorithm", is combined with the array partitioning technique based on droplet traces. The array partitioning and pin assignment methods are evaluated using a set of multiplexed bioassays.