A High-Performance Droplet Routing Algorithm for Digital Microfluidic Biochips

In this paper, we propose a high-performance droplet router for a digital microfluidic biochip (DMFB) design. Due to recent advancements in the biomicro electromechanical system and its various applications to clinical, environmental, and military operations, the design complexity and the scale of a DMFB are expected to explode in the near future, thus requiring strong support from CAD as in conventional VLSI design. Among the multiple design stages of a DMFB, droplet routing, which schedules the movement of each droplet in a time-multiplexed manner, is one of the most critical design challenges due to high complexity as well as large impacts on performance. Our algorithm first routes a droplet with higher by passibility which is less likely to block the movement of the others. When multiple droplets form a deadlock, our algorithm resolves it by backing off some droplets for concession. The final compaction step further enhances timing as well as fault tolerance by tuning each droplet movement greedily. The experimental results on hard benchmarks show that our algorithm achieves over 35 x and 20 x better routability with comparable timing and fault tolerance than the popular prioritized A* search and the state-of-the-art network-flow-based algorithm, respectively.