Low-Field Actuating Magnetic Elastomer Membranes Characterized using Fibre-Optic Interferometry.

Smart robotic devices remotely powered by magnetic field have emerged as versatile tools for wide biomedical applications. Soft magnetic elastomer (ME) composite membranes with high flexibility and responsiveness are frequently incorporated to enable local actuation for wireless sensing or cargo delivery. However, the fabrication of thin ME membranes with good control in geometry and uniformity remains challenging, as well as the optimization of their actuating performances under low fields (milli-Tesla).

Modification of Commercial Polymer Coatings for Superhydrophobic Applications.

Superhydrophobic surfaces have been studied extensively over the past 25 years. However, many industries interested in the application of hydrophobic properties are yet to find a suitable solution to their needs. This paper looks at the rapid functionalization of nanoparticles and the fabrication of superhydrophobic surfaces with contact angles > 170°.

Corrosion of One-Step Superhydrophobic Stainless-Steel Thermal Spray Coatings.

As most superhydrophobic coatings are made of soft materials, the need for harder, more robust films is evident in applications where erosional degradation is of concern. The work herein describes a methodology to produce superhydrophobic stainless-steel thermal spray coatings using the high-velocity oxygen fuel technique. Due to the use of a kerosene fuel source, a carbon-rich film is formed on the surface of the thermal spray coatings, lowering the surface energy of the high-energy metallic substrates.

Dual-scale TiO and SiO particles in combination with a fluoroalkylsilane and polydimethylsiloxane superhydrophobic/superoleophilic coating for efficient solvent-water separation.

Surfaces that have unique wettabilities and are simultaneously superhydrophobic with water contact angles > 150°, and superoleophilic with oil contact angles < 5°, are of critical importance in the oil/solvent-water separation field. This work details the facile preparation of highly efficient oil-water separation devices that successfully combine hierarchical surface roughening particles and low surface energy components with porous substrates. Coatings were generated using TiO and hydrophobic-SiO micro/nanoparticle loadings which were then embedded within polydimethylsiloxane, commercially known as Sylgard® 184, and 1,1,2,2-perfluorooctyltriethoxysilane (FAS) polymer mixtures.

Aerosol-assisted chemical vapour deposition of transparent superhydrophobic film by using mixed functional alkoxysilanes.

A method for the preparation of transparent superhydrophobic silica coatings on glass substrates via aerosol-assisted chemical vapour deposition (AACVD) is described. A multi-layer process to produce dual scale silica nanoparticles films, by using different functional alkoxysilanes was investigated. A first layer of 3-methacryloxypropyltrimethoxysilane (MPS) and a second layer of tetraethylorthosilicate (TEOS) were deposited at different temperatures to generate micro and nano particles of silica.

Inexpensive and non-toxic water repellent coatings comprising SiO nanoparticles and long chain fatty acids.

Special wettability durable coatings, with average water contact angles exceeding 140°, have been fabricated utilising functionalised hydrophobic-SiO (H-SiO) particles embedded in fatty acids. The inexpensive and non-toxic H-SiO particles imparted delicate lotus leaf inspired hierarchical surface nano-morphologies while the fatty acid modification afforded a suitable drop in surface energy. Comparison studies were carried out to explore the effects of fatty acid chain length and pipette as opposed to spray coating deposition methods on the coatings hydrophobicity.

The Anti-Biofouling Properties of Superhydrophobic Surfaces are Short-Lived.

Superhydrophobic surfaces are present in nature on the leaves of many plant species. Water rolls on these surfaces, and the rolling motion picks up particles including bacteria and viruses. Man-made superhydrophobic surfaces have been made in an effort to reduce biofouling.

Chemically Treated 3D Printed Polymer Scaffolds for Biomineral Formation.

We present the synthesis of nylon-12 scaffolds by 3D printing and demonstrate their versatility as matrices for cell growth, differentiation, and biomineral formation. We demonstrate that the porous nature of the printed parts makes them ideal for the direct incorporation of preformed nanomaterials or material precursors, leading to nanocomposites with very different properties and environments for cell growth. Additives such as those derived from sources such as tetraethyl orthosilicate applied at a low temperature promote successful cell growth, due partly to the high surface area of the porous matrix.

A Light-Activated Antimicrobial Surface Is Active Against Bacterial, Viral and Fungal Organisms.

Evidence has shown that environmental surfaces play an important role in the transmission of nosocomial pathogens. Deploying antimicrobial surfaces in hospital wards could reduce the role environmental surfaces play as reservoirs for pathogens. Herein we show a significant reduction in viable counts of Staphylococcus epidermidis, Saccharomyces cerevisiae, and MS2 Bacteriophage after light treatment of a medical grade silicone incorporating crystal violet, methylene blue and 2 nm gold nanoparticles.

Buoyancy increase and drag-reduction through a simple superhydrophobic coating.

A superhydrophobic paint was fabricated using 1H,1H,2H,2H-perfluorooctyltriethoxysilane (PFOTES), TiO nanoparticles and ethanol. The paint has potential for aquatic application of a superhydrophobic coating as it induces increased buoyancy and drag reduction. Buoyance testing showed that the reduction of surface energy by superhydrophobic coating made it feasible that glass, a high density material, was supported by the surface tension of water.

White light-activated antimicrobial surfaces: effect of nanoparticles type on activity.

Toluidine blue O (TBO) dye together with either silver (Ag) nanoparticles (NPs), gold (Au) NPs, or a mixture of Ag and Au NPs (Mix Ag-Au NPs) were incorporated into polyurethane to make antimicrobial surfaces using a swell-encapsulation-shrink process. Antimicrobial testing against Escherichia coli showed that inclusion of the NPs significantly enhanced the antimicrobial activities of the TBO polyurethane samples. In particular, samples containing Ag NPs exhibited potent antimicrobial activity under white light and surprisingly, also in the dark.

Functionalised gold and titania nanoparticles and surfaces for use as antimicrobial coatings.

We report the preparation, characterisation and antimicrobial functional testing of various titanium dioxide and gold modified titanium dioxide nanoparticles embedded into a polysiloxane polymer by a swell dip-coating procedure. We show that the surfaces are effective in killing both Gram-positive (Staphylococcus aureus) and Gram-negative (Escherichia coli) bacteria under different lighting conditions. The presence of the nanoparticles was of critical importance in improving the functional properties of the surface.

Polydimethylsiloxane coated glass frits for low-cost and reusable water-organic solvent separation.

A technique for functionalizing glass frits is described for use in separating water and organic solvents. The frits are coated with a hydrophobic-oleophilic silicone elastomer, giving rise to a reusable device that allows non-polar solvents to pass through but not water.