Liquid Body Formation from a Semispherical Superhydrophobic Well on a Small Incline

Abstract

In this work, drop formation on a slightly inclined superhydrophobic substrate with liquid at various flow rates delivered through a semispherical well was investigated. Due to the initial dry well condition in the first drop produced, the inertial force from liquid filling allowed the well's edge hysteresis to be more readily breached, in which flow rates of 16 mL/min and above could create a jet that appeared to be able to "pierce" through the top of the semispherical drop without disrupting its form and growth very much. For subsequent drops, the well's edge hysteresis at flow rates of 14 mL/min and above helped to support an "egg" like form. In contrast, this form could not be developed on a similarly inclined superhydrophobic substrate without a well. The findings here assist to establish the flow rate ranges for consistent discrete volume delivery in biochemical analysis and serves as a means to conduct investigations to better reconcile the tendency of liquids to assume drops or develop jets.

Brushed creation of liquid marbles

“…The former was essentially trying to "spread" itself to take advantage of its adhesion forces to the substrate, whereas the latter was attempting to adjust its shape in the absence of any adhesion forces. A similar demonstration of drops undergoing separate behaviors at its top and bottom was reported previously in another application context (Katariya & Ng, 2013;Katariya, Vuong & Ng, 2014). From tracking the contact length of the drop, it was found that the contact length of the drop increased appreciably as soon as contact with the foil was made.…”

Brushed creation of liquid marbles

“…The former was essentially trying to "spread" itself to take advantage of its adhesion forces to the substrate, whereas the latter was attempting to adjust its shape in the absence of any adhesion forces. A similar demonstration of drops undergoing separate behaviors at its top and bottom was reported previously in another application context [34,35]. From tracking the contact length of the drop, it was found that the contact length of the drop increased appreciably as soon as contact with the foil was made.…”

Plastron-Mediated Growth of Captive Bubbles on Superhydrophobic Surfaces

“…These routes will likely engender subtle shape departures, which are too small to observe with the naked eye. The ability to do this appears to be in contrast with the behavior of liquid bodies on SH surfaces, where contact line pinning is used to achieve significant shape changes in a continuous flow delivery …”

“…The ability to do this appears to be in contrast with the behavior of liquid bodies on SH surfaces, where contact line pinning is used to achieve significant shape changes in a continuous flow delivery. 29 At this juncture, we seek to account for the much larger diameters (relative to volume) attained previously, with values that are even higher than that computed for CA = 179°using Surface Evolver. 20 There, the mechanical interaction between the tip and bubble would reasonably have caused more significant shape changes to the gaseous body, thereby causing a larger departure from the dA LV /dA SL = cos θ condition.…”