Formal Synthesis of Adaptive Droplet Routing for MEDA Biochips
Mahmoud Elfara, Tung-Che Liangb, Krishnendu Chakrabartyc and and Miroslav Pajicd
Duke University, Durham NC, USA
amahmoud.elfar@duke.edu
btung.che.liang@duke.edu
ckrishnendu.chakrabarty@duke.edu
dmiroslav.pajic@duke.edu
ABSTRACT
A digital microfluidic biochip (DMFB) enables the miniaturization of immunoassays, point-of-care clinical diagnostics, and DNA sequencing. A recent generation of DMFBs uses a micro-electrode-dot-array (MEDA) architecture, which provides fine-grained control of droplets and real-time droplet sensing using CMOS technology. However, microelectrodes in a MEDA biochip can degrade due to charge trapping when they are repeatedly charged and discharged during bioassay execution; such degradation leads to the failure of microelectrodes and erroneous bioassay outcomes. To address this problem, we first introduce a new microelectrode-cell design such that we can obtain the health status of all the microelectrodes in a MEDA biochip by employing the inherent sensing mechanism. Next, we present a stochastic game-based model for droplet manipulation, and a formal synthesis method for droplet routing that can dynamically change droplet transportation routes. This adaptation is based on the real-time health information obtained from microelectrodes. Comprehensive simulation results for four real-life bioassays show that our method increases the likelihood of successful bioassay completion with negligible impact on time-to-results.
