Fault Modeling and Simulation of MEDA Based Digital Microfluidics Biochips

The research in the area of digital micro fluidics biochips testing is rapidly growing. The recently proposed Micro-electrode Dot Array (MEDA) based digital micro fluidics architecture allows dynamic grouping of the micro-electrodes to form the desired shape of droplets. As these kinds of system are used in safety critical applications, their reliability is crucial. The testing of MEDA architecture is a challenging problem due to the involvement of multiple micro-electrodes for various operations. This paper presents the fault models associated with the MEDA architecture for one as well as multiple micro-electrodes. An oscillation based testing model is proposed to measure the frequency of the droplet in fault free and faulty case in terms of capacitance variation, which is shown to be directly related to the droplet volume. Simulation results from oscillation based testing model for the case of droplet electrode short fault shows a significant increase in the oscillation frequency as the capacitance of droplet decreases.