Checkpoint-Aware Droplet Routing Avoiding Cross-Contamination on Cyber-Physical Cross-Referencing DMFBs

A Digital Microfluidic Biochip (DMFB) performs several bioassays involving discrete fluid droplets with high precision, which is prone to actuation tampering attacks in real-life scenarios. Static checkpoints (optical sensors) are embedded to detect such attacks. Cross-contamination (in any cell, including checkpoint) is an unavoidable issue while reusing the on-chip resources. Moreover, electrode interference problem is another key problem of droplet routing on biochips with low number of pins like cross-referencing biochips. Neither checkpoint-contamination nor electrode interference have been considered in the existing works regarding checkpoint-aware routing. Our proposed method performs a cross-contamination-aware checkpoint assignment on a cross-referencing biochip, followed by an electrode interference free checkpoint-aware routing, intra-, and inter-assay washing to ensure overall safety of an assay operation.