Deformation and relaxation of viscous thin films under bouncing drops

Abstract

Abstract

Droplet Bouncing: Fundamentals, Regulations, and Applications

“…[80] Lakshman et al further investigated the precise deformation of the lubricant liquid during and after the droplet impact with the help of the digital holographic microscopy. [49] The droplet bouncing behavior on the surface infused with lubricant can further broaden the applications of slippery surface with lubricant oil.…”

“…With the help of the interferometry, the temporal air layer thickness can be observed in nanoscale (Figure 4c). [ 48 ] A bell‐like shape of the air layer is observed, whose maximum thickness is at the center of the air layer, [ 48,49 ] and the high viscosity of the liquid film is beneficial to the droplet bouncing. [ 50 ]…”

Bouncing drops over liquid surfaces

“…The Digital Holographic Microscopy (DHM ® -R1000 from Lyncée Tec), allows for real-time measurements with a vertical resolution of (at least) 20 nm. For details on measuring film deformation using the DHM technique, refer to Chapter 2 of the thesis and Lakshman et al [66].…”

“…figure 4.17b and 4.17d) the holography measurement cannot be trusted quantitatively. This is due to the fact that small air gaps ∼ 100 µm cause additional light reflections which interfere with the film deformation measurements [66].…”

“…In the limit of thin enough viscous coatings, the substrate mimics an atomically smooth solid and displays a superamphiphobic-like repellent behavior [47,78]. This substrateindependent bouncing [44,78,89,66] can be compared with that observed on superhydrophobic substrates, where the apparent contact time is given by the oscillation time of a drop [103], owing to the drop impact-oscillation analogy [110]. However, unlike ideal Rayleigh oscillations, the collisions are partially inelastic due to viscous dissipation [98].…”