Electrowetting control of bouncing jets

Xavier Noblin (1) , Franck Celestini (1)

1 LPMC - Laboratoire de physique de la matière condensée

As recently studied, a sub-millimetric liquid jet can bounce on sufficiently hydrophobic surfaces [F.Celestini et al., Soft Matter 6(23), 5872-5876 (2010); A. Kibar et al., Exp. Fluids 49(5), 1135-1145 (2010)]. As the hydrophobicity is reduced, the reflection angle (\theta_r) increases and the jet rebound deviates more and more from specular reflection. In the present study, we vary the wetting properties of the substrate using the electrowetting effect to induce a change in the reflection angle. A liquid jet is sent toward a metallic surface coated by an insulating, hydrophobic layer. Applying an ac voltage between the metallic nozzle and the electrode below the insulating layer, we can precisely control the reflection angle of the jet. The effects of the amplitude and the frequency of the applied voltage are analyzed. This study can find applications for the control of jet dynamics.

Mots clés: Wetting Jets Electrowetting

Domaines: Matière Molle [cond-mat.soft]

Xavier Noblin, Franck Celestini. Electrowetting control of bouncing jets. Applied Physics Letters, 2012, 101, pp.094101. ⟨10.1063/1.4747199⟩. ⟨hal-00727107⟩