Automated design of pin-constrained digital microfluidic biochips under droplet-interference constraints

Microfluidics-based biochips, also referred to as lab-on-a-chip, are devices that integrate fluid-handling functions such as sample preparation, analysis, separation, and detection. This emerging technology combines electronics with biology to open new application areas such as point-of-care diagnosis, on-chip DNA analysis, and automated drug discovery. We propose a design automation method for pin-constrained biochips that manipulate nanoliter volumes of discrete droplets on a microfluidic array. In contrast to the direct-addressing scheme that has been studied thus far in the literature, we assign a small number of independent control pins to a large number of electrodes in the biochip, thereby reducing design complexity and product cost. The design procedure relies on a droplet-trace-based array partitioning scheme and an efficient pin assignment technique, referred to as the “Connect-5 algorithm.” The proposed method is evaluated using a set of multiplexed bioassays.