The impact of the vertical gap between plates on the droplet splitting in a covered digital microfluidic system driven by electrowetting is discussed.Firstly

the system is modeled with the level set method.Then a finite element software is used to simulate the splitting process.With the fixed electrode length and different vertical gaps between the top plate and the bottom plate

the changes of the total press and the velocity of contact lines is discussed

and the simulation results is evaluated.Finally

a ratio range of electrode length to plate gap that may split the droplet effectively is given

which provides a reference for the chip design.