Distributed Scan Like Fault Detection and Test Optimization for Digital Microfluidic Biochips

Development of digital microfluidic biochips (DMFB) has faced a major setback from the threats of faulty and erroneous fluidic operations. Defective electrodes are the main reason for this misleading assay performance. It also affects the assay completion time and overall turnaround time. In this present article, a fast fault diagnosis mechanism is discussed to identify the defective locations of electrode array. The proposed fault detection method is governed by a distributed dispensing and scheduling of test droplets on a 2-D biochip. Water droplets are strategically routed across the DMFB board and quantified at every location using cost effective photodiode sensors. Multiple test droplets are routed on the chip in a time synchronized manner to avoid any routing conflict or failure in diagnosis. This concurrent test droplet circulation incurs optimum layover period and parallel and multiple test droplet movement enhances the fault detection performance. Completeness of the fault analysis is ensured with a sequential post processing as well. Test results of this approach have recorded some substantial improvement in terms of fault detection time and accuracy.