A compiler for cyber-physical digital microfluidic biochips

Abstract

Programmable microfluidic laboratories-on-a-chip (LoCs) offer the benefits of automation and miniaturization to the life sciences. This paper presents an updated version of the BioCoder language and a fully static (offline) compiler that can target an emerging class of LoCs called Digital Microfluidic Biochips (DMFBs), which manipulate discrete droplets of liquid on a 2D electrode grid. The BioCoder language and runtime execution engine leverage advances in sensor integration to enable specification, compilation, and execution of assays (bio-chemical procedures) that feature online decision-making based on sensory data acquired during assay execution. The compiler features a novel hybrid intermediate representation (IR) that interleaves fluidic operations with computations performed on sensor data. The IR extends the traditional notions of liveness and interference to fluidic variables and operations, as needed to target the DMFB, which itself can be viewed as a spatially reconfigurable array. The code generator converts the IR into the following: (1) a set of electrode activation sequences for each basic block in the control flow graph (CFG); (2) a set of computations performed on sensor data, which dynamically determine the result of each control flow operation; and (3) a set of electrode activation sequences for each control flow transfer operation (CFG edge). The compiler is validated using a software simulator which produces animated videos of realistic bioassay execution on a DMFB.