Fault diagnosis for lab-on-chip using digital microfluidic logic gates

Dependability is an important system attribute for microfluidic lab-on-chip systems. Robust testing and diagnosis methods are therefore needed for a lab-on-chip. Previously proposed techniques for reading test outcomes and for pulse-sequence analysis are cumbersome and error-prone. We present a fault diagnosis method to locate a single defective cell and multiple rows/columns with defective cells in a digital microfluidic array. This method utilizes digital microfluidic exclusive-or gates to implement an output compactor. The microfluidic compactor can compress 2^r distinct test outcomes to a r-droplet signature. This approach obviates the need for capacitive sensing test-outcome circuits for analysis.