System prototype for 2D large scaled EWOD chip

A system-level prototype for EWOD driving was proposed and built, to aim the goal of droplet manipulation in 2D large scaled EWOD chip for biological detection.

When a 2D large scale EWOD chip is applied into application, there is still challenge in control of independent electrode for flexible applications. Droplet residues on electrode or any defects in the dielectrics would cause failures of droplet manipulation or detection accuracy. Therefore, effective control of electrodes, and discovery of the sites of the bugs and real-time routing for dodging of them are important for biological detections. We proposed a direct address and passive controlling method with N+M pins for M+N electrodes, and an electrical impedance-based sensing method for the bug finding. Lee algorithm was applied to automatically route droplet with real-time feedback of the bugs in the 2D EWOD chip with 10´10 electrode matrix. Hardware and software were developed applicable for 2D large scale EWOD chips.

Fig. 1 shows the schematic and picture of the system and the signal flow among the circuit components. Fig. 2 demonstrates the manipulation of multiple droplets simultaneously without conflict. Fig.3 gives the detection of the sites and sizes of the droplet residue larger than 40% of that of the electrode. Fig.4 expresses the real-time routing to dodging the bugs successfully.