We present a novel and simple method to manipulate droplets applicable to an open-surface microfluidic platform. The platform comprised a control module for pneumatic droplets and a superhydrophobic polydimethylsiloxane (PDMS) membrane. With pneumatic suction to cause deflection of the flexible PDMS-based superhydrophobic membrane, the sample and reagent droplets on the membrane become transpor...

The present study demonstrates a surface structure that mimics the water harvesting wing surface of the Namib Desert beetle. Hydrophilic patterns on superhydrophobic surfaces were created with water/2-propanol solutions of a polyelectrolyte to produce surfaces with extreme hydrophobic contrast. Selective deposition of multilayer films onto the hydrophilic patterns introduces different propertie...

Superhydrophobic films were fabricated on a titanium substrate with or without anodizing by using a self-assembling method. Firstly, the pretreatments of mechanical polishing/anodizing or mechanical polishing only were conducted, respectively. Subsequently, the preparation of polydopamine film layer, deposition of nano-silver particles, and post modification of 1H,1H,2H,2H-perfluorodecanethiol ...

For a liquid droplet to slide down a solid planar surface, the surface usually has to be tilted above a critical angle of approximately 10°. By contrast, droplets of nearly any liquid "slip" on lubricant-infused textured surfaces - so termed slippery surfaces - when tilted by only a few degrees. The mechanism of how the lubricant alters the static and dynamic properties of the drop remains elus...

Using plasma in conjunction with fluorinated compounds is widely encountered in material processing. We discuss several plasma techniques for surface fluorination: deposition of fluorocarbon thin films either by magnetron sputtering of polytetrafluoroethylene targets, or by plasma-assisted chemical vapor deposition using tetrafluoroethane as a precursor, and modification of carbon nanowalls by ...

By using characteristics of titania nanoparticles, a patterning and tuning method of microchannel surface wettability was developed for microfluid control. Titania modification of a microchannel provided a nanometer-sized surface roughness and the subsequent hydrophobic treatment made the surface superhydrophobic. Photocatalytic decomposition of the coated hydrophobic molecules was used to patt...

We describe a one-step method for creating thousands of isolated pico- to microliter-sized droplets with defined geometry and volume. Arrays of droplets are instantly formed as liquid moves along a superhydrophilic-superhydrophobic patterned surface. Bioactive molecules, nonadherent cells, or microorganisms can be trapped in the fully isolated microdroplets for high-throughput screening, or in ...

A new type of superhydrophobic material, FP-Co-SiO(2) was prepared with organic groups immobilized on the surface of the SiO(2)-based nanocomposite. This material showed much higher catalytic activity for selective oxidation of hydrocarbons than an equivalent hydrophilic catalyst.

Many natural superhydrophobic structures have hierarchical two-tier roughness which is empirically known to promote robust superhydrophobicity. We report the wetting and dewetting properties of two-tier roughness as a function of the wettability of the working fluid, where the surface tension of water/ethanol drops is tuned by the mixing ratio, and compare the results to one-tier roughness. Whe...

A new and facile assay for hydroxyl radicals in photocatalytic systems is reported for the first time that is based on the fluorescence imaging of increasing hydrophilic regions through the highly selective hydroxyl radical-induced lateral remote oxidation of superhydrophobic 1-octadecanethiol molecules at gold flower-like surface in the designed photomask setup.