Full text loading...
Schematic of the experimental setup. The microfluidic channels were fabricated in poly(dimethylsiloxane) (PDMS). Each of the main channels (light shaded) had a length of 1.1 cm. The heights of the main channels and the exit channels (dark shaded) were , and the widths were for the main channels and for the exit channels. The circular area shows the details of the small channel constriction (orifice), with the right entrance being where the immiscible interface was maintained prior to initiating the pulse; the immiscible phase was silicone oil (density of and dynamic viscosity of 20 mPa s at 25 °C) mixed with 3% Span 85. Voltage pulses were applied using a custom-built high-voltage pulse generator with additional circuits to rapidly discharge voltage during the trailing edge of the pulse. The images were acquired with an inverted microscope (Nikon TE 300, Nikon, Tokyo, Japan) and a high-speed camera (CPL-MS10K, Canadian Photonic Labs, Minnedosa, Manitoba, Canada).
(a) Sequence of images showing the formation of the Taylor cone and the subsequent relaxation of the interface upon application of a single voltage pulse (900 V, 50 ms). (b) Dynamic displacement of the vertex as a function of time under pulse durations of 50 ms (crosses) and 20 ms (circles), both at 900 V. The inset shows the superposition of the applied voltage pulse (solid line) and the observed vertex displacement (crosses). (c) The maximum displacement of the vertex of the aqueous phase in 20 ms as a function of the pulse amplitude. Inset: the equilibrium cone angle of the Taylor cone.
(a) Sequence of images showing the generation of a single droplet upon application of a voltage pulse (800 V, 10 ms). (b) Plot of the droplet diameter vs the jet diameter collected over various pulse amplitudes and durations. Inset: distribution of the ratio of droplet-to-jet diameter.
Article metrics loading...