Recent advances in digital microfluidics have led to tremendous interest inminiaturized lab-on-a-chip devices for biochemical analysis. Synthesis toolshave also emerged for the automated design of lab-on-a-chip from thespecifications of laboratory protocols. However, none of these toolsconsiders control flow or addresses the problem of recovering from fluidicerrors that can occur during on-chip bioassay execution. We present asynthesis method that incorporates control paths and an error-recoverymechanism in the design of a cyberphysical digital microfluidiclab-on-a-chip. A microcontroller coordinates the implementation of thecontrol-flow-based bioassay by intercepting the synthesis results that aremapped to the software programs. Real-life bioassay applications are used ascase studies to evaluate the proposed design method. For a representativeprotein assay, compared with a baseline chip design, the biochip with acontrol path can reduce the completion time by 30% when errors occur duringthe implementation of the bioassay. A fabricated biochip is also used todemonstrate cyberphysical error recovery in a laboratory setting.

Introduction

Microfluidic biochips have now come of age, with applications to biomolecularrecognition for high-throughput DNA sequencing, immunoassays, andpoint-of-care clinical diagnostics [1]. In particular, digital microfluidicbiochips, which use electrowetting-on-dielectric to manipulate discretedroplets (or “packets of biochemical payload”) of picolitervolumes under clock control, are especially promising [2].