Role of wettability and electric field on droplet splitting dynamics in T-shaped branched microchannel

The present work discusses the dynamics of droplet formation and splitting in a T-shaped branched microchannel under the influence of an electric field using the two-phase level set method (LSM). A thorough investigation is conducted to gain insight into the interplay of wettability, flow rate ratio, and electric fields on droplet splitting in a branched T-junction microchannel. A direct current (DC) electric field is applied to the top outlet branch while maintaining a zero-charge boundary condition on other surfaces. The wettability of the bottom outlet branch is systematically varied between hydrophilic ϴb=78°, hydrophobic ϴb=115°, and superhydrophobic ϴb=150°, while the top outlet branch remains hydrophilic ϴt=78°. The effects of flow rate ratio (Q), dispersed phase inlet position, and channel geometry are analyzed to assess their influence on droplet deformation, splitting ratio (SR), and splitting time (τ). Results reveal that higher electric field strengths promote faster droplet splitting, with significant changes observed in the droplet morphology and volume distribution. Wettability significantly impacts droplet dynamics, with hydrophilic surfaces enhancing uniform splitting and superhydrophobic surfaces favoring bypass behavior. Increasing flow rate ratios reduces splitting time and improves redistribution efficiency, while shorter inlet travel distances result in distinct splitting patterns due to reduced droplet stabilization. Considering the influence of the electric field on the wall wettability leads to increased spreading of the droplet along the top outlet branch. These findings offer valuable insights for optimizing droplet behavior in microfluidic devices, with potential applications in chemical processing, drug delivery, and material synthesis.