Exact Routing for Digital Microfluidic Biochips with Temporary Blockages

Digital microfluidic biochips enable a higher degree of automation in laboratory procedures in biochemistry and molecular biology and have received significant attention in the recent past. Their design is usually conducted in several stages with routing being a particularly critical challenge. Previously proposed solutions for this design step suffer from two issues: They are mainly of heuristic nature and usually assume that the blockages to be bypassed are present the entire time. In contrast, we present a methodology which exploits the fact that blockages are often only present at certain intervals. At the same time, our approach guarantees exact solutions, i.e. always determines a routing with a minimal number of time steps. Experimental results show that, despite the huge complexity, optimal results can be achieved in reasonable run-time and that the consideration of temporary blockages indeed significantly improves the routing results.