Distribution of Articles published per year
(1987 - 2018)
(1987 - 2018)
Total number of journals
Publications See all
Article 0 Reads 0 Citations Apparent Contact Angles on Lubricant-Impregnated Surfaces/SLIPS: From Superhydrophobicity to Electrowetting Published: 05 March 2019
Langmuir, doi: 10.1021/acs.langmuir.8b04136
Article 0 Reads 0 Citations Pinning-Free Evaporation of Sessile Droplets of Water from Solid Surfaces Published: 31 January 2019
Langmuir, doi: 10.1021/acs.langmuir.8b03849
Article 0 Reads 0 Citations Dielectrowetting: The past, present and future Published: 01 July 2018
Current Opinion in Colloid & Interface Science, doi: 10.1016/j.cocis.2017.11.005
Liquid dielectrophoresis is a bulk force acting on dipoles within a dielectric liquid inside a non-uniform electric field. When the driving electrodes are interdigitated, bulk liquid dielectrophoresis is converted to an interface-localised form capable of modifying the energy balance at an interface. When the interface is a solid-liquid one, the wetting properties of a surface are modified and this approach is known as dielectrowetting. Dielectrowetting has been shown to provide the ability to reversibly modify the contact angle of a liquid droplet with the application of voltage, the strength of which is controlled by the penetration depth of the non-uniform field and permittivities of the fluids involved. Importantly, dielectrowetting provides the ability to create thin liquid films, overcoming the limitation of contact angle saturation present in electrowetting. In this paper, we review the development of dielectrowetting - its origins, the statics and dynamics of dielectrowetted droplets, and the applications of dielectrowetting in microfluidics and optofluidics. Recent developments in the field are also reviewed showing the future directions of this rapidly developing field.
Article 0 Reads 0 Citations Bimorph material/structure designs for high sensitivity flexible surface acoustic wave temperature sensors Published: 13 June 2018
Scientific Reports, doi: 10.1038/s41598-018-27324-1
A fundamental challenge for surface acoustic wave (SAW) temperature sensors is the detection of small temperature changes on non-planar, often curved, surfaces. In this work, we present a new design methodology for SAW devices based on flexible substrate and bimorph material/structures, which can maximize the temperature coefficient of frequency (TCF). We performed finite element analysis simulations and obtained theoretical TCF values for SAW sensors made of ZnO thin films (~5 μm thick) coated aluminum (Al) foil and Al plate substrates with thicknesses varied from 1 to 1600 μm. Based on the simulation results, SAW devices with selected Al foil or plate thicknesses were fabricated. The experimentally measured TCF values were in excellent agreements with the simulation results. A normalized wavelength parameter (e.g., the ratio between wavelength and sample thickness, λ/h) was applied to successfully describe changes in the TCF values, and the TCF readings of the ZnO/Al SAW devices showed dramatic increases when the normalized wavelength λ/h was larger than 1. Using this design approach, we obtained the highest reported TCF value of −760 ppm/K for a SAW device made of ZnO thin film coated on Al foils (50 μm thick), thereby enabling low cost temperature sensor applications to be realized on flexible substrates.
Article 0 Reads 0 Citations Statics and dynamics of liquid barrels in wedge geometries Published: 06 March 2018
Journal of Fluid Mechanics, doi: 10.1017/jfm.2018.116
Article 0 Reads 1 Citation Bioinspired nanoparticle spray-coating for superhydrophobic flexible materials with oil/water separation capabilities Published: 02 February 2018
Bioinspiration & Biomimetics, doi: 10.1088/1748-3190/aaa1c1
Much of the inspiration for the creation of superhydrophobic surfaces has come from nature, from plant such as the Sacred Lotus (Nulembo nucifera), where the micro-scale papillae epidermal cells on the surfaces of the leaves are covered with nano-scale epicuticular wax crystalloids. The combination of the surface roughness and the hydrophobic wax coating produces a superhydrophobic wetting state on the leaves allowing them to self-clean and easily shed water. Here a simple scale-up carbon nanoparticle spray coating is presented that mimics the surface of the Sacred Lotus leaves and can be applied to a wide variety of materials, complex structures, and flexible substrates, rendering them superhydrophobic, with contact angles above 160°. The sprayable mixture is produced by combining toluene, polydimethylsiloxane (PDMS), and inherently hydrophobic rapeseed soot. The ability to spray the superhydrophobic coating allows for the hydrophobisation of complex structures such a metallic meshes, which allows for the production of flexible porous superhydrophobic materials that when formed into U-shape channels, can be used to direct flows. The porous meshes, whilst being superhydrophobic, are also oleophilic. Being both superhydrophobic and oleophilic allows oil to pass through the mesh, whilst water remains on the surface. The meshes were tested for their ability to separate mixtures of oil and water in a flow situation. When silicone oil/water mixtures were passed over the meshes, all meshes tested were capable of separating more than 95% of the oil from the mixture.