Controlling the impact dynamic behavior of a water-in-oil compound drop using the dielectrowetting effect

Controlling the impact dynamic behavior of a water-in-oil compound drop is vital for applications such as the enhancement of printing resolution and the preparation of innovative liquid-separation materials and devices. A phase diagram is constructed between the impact behavior, Weber number, and equilibrium contact angle of the water drop. The dynamic impact behavior of water-in-oil compound drops can be effectively controlled by changing the surface wettability using the dielectrowetting effect. The maxi-mum spreading factor bm at different wettabilities shares a similar scale law bm << We0:17 for 45.75 < W e < 299.62 and bm << We0:23 for 385.38 < We < 1183.19. Finally, the relationship between the velocity and radius of the rebounded drops was consistent with the results for pure water drops. Our findings indicate that the impact behavior of water-in-oil compound drops can be controlled at the right time scales using a dielectrowetting substrate; this is applicable in industries such as printing and liquid separation. (c) 2023 Elsevier Ltd. All rights reserved.