Collisional ferrohydrodynamics of magnetic fluid droplets on superhydrophobic surfaces

Marangoni convection in droplets on superhydrophobic surfaces

We consider a small droplet of water sitting on top of a heated superhydrophobic surface. A toroidal convection pattern develops in which fluid is observed to rise along the surface of the spherical droplet and to accelerate downwards in the interior towards the liquid/solid contact point. The internal dynamics arise due to the presence of a vertical temperature gradient; this leads to a gradie...

Switchable static and dynamic self-assembly of magnetic droplets on superhydrophobic surfaces.

Self-assembly is a process in which interacting bodies are autonomously driven into ordered structures. Static structures such as crystals often form through simple energy minimization, whereas dynamic ones require continuous energy input to grow and sustain. Dynamic systems are ubiquitous in nature and biology but have proven challenging to understand and engineer. Here, we bridge the gap from...

Friction and Wetting Transitions of Magnetic Droplets on Micropillared Superhydrophobic Surfaces.

Reliable characterization of wetting properties is essential for the development and optimization of superhydrophobic surfaces. Here, the dynamics of superhydrophobicity is studied including droplet friction and wetting transitions by using droplet oscillations on micropillared surfaces. Analyzing droplet oscillations by high-speed camera makes it possible to obtain energy dissipation parameter...

Probing droplets on superhydrophobic surfaces by synchrotron radiation scattering techniques

Droplets on artificially structured superhydrophobic surfaces represent quasi contact-free sample environments which can be probed by X-ray microbeams and nanobeams in the absence of obstructing walls. This review will discuss basic surface wettability concepts and introduce the technology of structuring surfaces. Quasi contact-free droplets are compared with contact-free droplets; processes re...

Sliding droplets on hydrophilic/superhydrophobic patterned surfaces for liquid deposition