Retention Time Constrained Bioassay Scheduling on Flow-Based Microfluidic Biochips with Latches

Scheduling of mixing graphs is the first step of the design automation for the implementation of mixing graphs on microfluidic biochips. Depending on the biochip platform, the scheduling constraints may vary. For instance, if we consider a flow-based microfluidic biochip, then we have to consider the retention time while scheduling any mixing graph. The retention time of a flow-based microfluidic biochip is defined as the duration for which a latch valve can hold the pressure for a given pressure pulse and act as a normal valve. Violating retention time constraint can produce erroneous results for on-chip bioprotocol execution. Recently one method called time aware list scheduling (TALS) is reported in literature, which considers the retention time constraint while scheduling the mixing graphs without minimizing the scheduling length. However, the quality of a scheduling algorithm depends on the trade-off between the resource required and the scheduling length. In this work, we consider the retention time of latches as the scheduling constraint and proposed a novel heuristic-based approach called retention time aware scheduling (RTAS) that aims to minimize the scheduling length with slight increase in number of resources (on-chip mixers) required. Simulation results confirm that RTAS always outperforms the baseline ALAP and TALS in case of resources required and the scheduling length, respectively.