Reversible Switching of Water‐Droplet Mobility on a Superhydrophobic Surface Based on a Phase Transition of a Side‐Chain Liquid‐Crystal Polymer

Abstract

Reversible switching of the mobility of a water microdroplet between rollable and pinned simply by changing the temperature is realized by coordination of the phase transition of a side‐chain liquid‐crystal polymer (SCLCP) with optimized surface roughness of a superhydrophobic surface. The responsive surface has potential applications in microreactor design and microfluidic control systems.

Reversible conversion of water-droplet mobility from rollable to pinned on a superhydrophobic functionalized carbon nanotube film

“…To design more innovative microfluidic devices, the combination of superhydrophobic property and reversible conversion of water mobility would be desirable. Recently, superhydrophobic surfaces with tunable water-droplet mobility have attracted increasing interest [10][11][12][13][14][15][16]. Lin and co-works reported the fabrication of superhydrophobic nanostructure TiO 2 surfaces with tunable water adhesion via the control of surface chemical components [11] and surface nanostructures [12].…”

External‐Field‐Induced Gradient Wetting for Controllable Liquid Transport: From Movement on the Surface to Penetration into the Surface

“…[108][109][110][111][112][113][114][115][116] Jiang's group have made a large contribution to this field. [108][109][110] Water-droplet adhesion switching has been achieved by the thermoresponsive phase transition of the n-paraffin-swollen organogel surface for water-droplet movement control. [37,87] Similar results have been obtained on a side-chain liquid-crystal polymer surface by temperature, owing to the phase transition from the smectic A phase to the isotropic phase.…”

“…[37,87] Similar results have been obtained on a side-chain liquid-crystal polymer surface by temperature, owing to the phase transition from the smectic A phase to the isotropic phase. [108] Furthermore, underwater oil and cell adhesion can also be reversibly controlled by temperatures lower or higher than the lower critical solution temperature at the water/solid interface containing PNIPAAm. [108,109] These thermoresponsive surfaces are promising in the field of biomedicine, biomaterials, and other blood-compatible materials.…”

“…[108] Furthermore, underwater oil and cell adhesion can also be reversibly controlled by temperatures lower or higher than the lower critical solution temperature at the water/solid interface containing PNIPAAm. [108,109] These thermoresponsive surfaces are promising in the field of biomedicine, biomaterials, and other blood-compatible materials.…”

Peach skin effect: a quasi-superhydrophobic state with high adhesive force

“…Superhydrophobic adhesion surfaces in the biological field provide us with inspiration for the preparation of some novel functional surface materials. Bioinspired superhydrophobic adhesive surfaces with a large contact angle and high contact angle hysteresis are important in smart and fluid-controllable devices [19][20][21], such as no-loss reversible transport of microliter-sized super-paramagnetic liquid droplets by alternating magnetic fields [19].…”