Design of EWOD device with suspended ground electrode

This paper researches how to design the suspended ground electrode of an electrowetting-on-dielectric(EWOD)based device, because most of the existing investigations for the efficiency of single-plate EWOD device were carried out by means of numerical simulations and lack of experimental results. Then, it coampares, the driving effectiveness for a liquid droplet by the proposed EWOD device with suspended ground electrode and a traditional bipolar plate device. Based upon the theory of the EWOD, the dielectric, deriving EWOD force and each resistive force of the droplet holding between the bipolar plates were derived, and the forces of the droplet sitting on the single-plate EWOD device were analyzed. Then, the forces were compared between the bipolar plate device and the single-plate EWOD device. Finally, the driving characteristics of the droplet were tested via the fabricated EWOD device. The experimental results show that the driving voltage of single-plate is more low, and its velocity is more faster than that of the bipolar plates; the velocity of 1 μL droplet can be 15 cm/s when the driving potential is 44 V_RMS. In conclusion, the obtained experimental results validate the feasibility of the single-plate EWOD device with suspended ground electrode for its faster velocity and low driving potential.