Wettability-confined liquid-film convective cooling: Parameter study

Controllable Directional Liquid Transport in Open Channel

“…[33] Megaridis and coworkers used wedge-shaped wettability patterns to achieve directional liquid flow on polymer, metal and porous material surfaces, and applied it to micromixer, lab-on-chip, and thermal management. [34][35][36][37] Upadhyay and Waghmare demonstrated underwater oil transport and oil/water separation on copper surfaces with wettability contrast prepared by vapor-based etching method. [38] Despite of these remarkable progress in directional liquid transport, on-demand switch of liquid transport on the wettability-engineered surface needs to be investigated.…”

Lateral Spreading of Gas Bubbles on Submerged Wettability-Confined Tracks

“…It is important to note that the side faces of the elevated track were also scraped during this process. This rendered the track’s top surface superhydrophobic (likewise, superaerophilic), while the rest of the surrounding substrate was superhydrophilic (likewise, superaerophobic). It is noted that at the edge of the track where the bubble was dispensed, the superaerophobic and superaerophilic domains were at the same elevation.…”

“…The advancement of surface engineering techniques has facilitated scalable approaches for fabricating wettable and nonwettable surfaces, on which a variety of liquids can be manipulated. Distinctly different behaviors of fluids encountering wettable and nonwettable surfaces enable effective confinement of liquid volumes on surfaces possessing spatially juxtaposed wettable and nonwettable domains separated by a sharp wettability-contrast line. − The scientific literature from the last two decades bears testimony to the applicability of wettability-patterned surfaces in open-surface microfluidics, pool boiling, condensation, , and electronics cooling. , A superhydrophobic (water-repelling) surface behaves as a superaerophilic (air-attracting) one when submerged in water, and vice versa for a superhydrophilic surface. , A review of the various fabrication techniques for obtaining superaerophobic and superaerophilic surfaces was recently presented by George et al Numerous studies have shown possible applications of such surfaces in gas harvesting, − wastewater remediation, catalytic action, drag reduction, etc.…”

Ultrafast Propulsion of Water Nanodroplets on Patterned Graphene

“…[13][14][15] The effect of wettability patterning on heat transfer 16 was also investigated by studies that were focused on enhancing the cooling efficiency of microelectronic devices by guiding water on a hydrophilic wedge-shaped track surrounded by superhydrophobic terrains. [17][18][19] The potential of wettability gradients for enhanced uni-directional liquid transport at the 2 nano-and micro-scale has received significant attention for fast drug delivery, efficient heat transport 20,21 and electricity generation; 22 such gradients are considerably easier to manufacture than other structural patterns. 8 The static contact angle exhibited by water droplets on graphene is one of the common fundamental configurations for comparing experimental and computational studies and validating MD potentials.…”

“…Nano- and microstructural and chemical surface patterns are encountered on insect bodies and plant leaves and are frequently associated with the vital functions of organisms. , In turn, the interactions of natural nano/microstructures with liquids serve as inspiration for engineered surfaces meant to increase transport efficiency, liquid collection, or condensation and heat transfer of micro- and nanodroplets. − A prominent example is the water-collection system of the Namib desert beetle, exhibiting surfaces exploited for water collection and directional transport . Experimental studies inspired by these surfaces have successfully demonstrated the water harvesting mechanisms in the microscale regime. , Another example involves the structure of the vein network of the banana tree leaves, which has inspired the construction of patterned hydrophilic surfaces for microscale systems of higher heat transfer efficiency. − The effect of wettability patterning on heat transfer was also investigated by studies that were focused on enhancing the cooling efficiency of microelectronic devices by guiding water on a hydrophilic wedge-shaped track surrounded by superhydrophobic terrains. − …”