Experimental demonstration of error recovery in an integrated cyberphysical digital-microfluidic platform

Digital (droplet-based) microfluidics enables the integration of fluid-handling operations and reaction-outcome detection. Despite these benefits, defects and erroneous fluidic operations continue to be major barriers to the adoption and deployment of these devices. We describe the first practical and fully integrated cyberphysical error-recovery system that can be implemented in real time on a field-programmable gate array (FPGA). The hardware-assisted solution is based on an error dictionary containing the error-recovery plans for various anticipated errors. The dictionary is computed and stored in FPGA memory before the start of the biochemical experiment. Errors in droplet operations on the digital microfluidic platform are detected using capacitive sensors, the test outcome is interpreted by control hardware, and corresponding error-recovery plans are triggered in real-time. Experimental results are reported for a fabricated silicon device, and links to videos are provided for the first-ever experimental demonstration of real-time error recovery in cyberphysical digital-microfluidic biochips using a hardware-implemented dictionary.