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Glen McHale  - - - 
Top co-authors See all
Robert H. Morris

143 shared publications

School of Science and Technology, Nottingham Trent University, Clifton Lane, Nottingham, NG11 8NS, UK

Michael I. Newton

92 shared publications

School of Science and Technology; Nottingham Trent University; Nottingham UK

Khellil Sefiane

72 shared publications

School of Engineering, University of Edinburgh, The King's Buildings, Mayfield Road, Edinburgh EH9 3FB, United Kingdom

C. V. Brown

64 shared publications

School of Science and Technology, Nottingham Trent University, Clifton Lane, Nottingham NG11 8NS, United Kingdom

Jonathan Terry

63 shared publications

SMC, Institute for Integrated Micro and Nano Systems, School of Engineering, The University of Edinburgh, Edinburgh EH9 3JF, United Kingdom

Publication Record
Distribution of Articles published per year 
(1987 - 2019)
Total number of journals
published in
Publications See all
PROCEEDINGS-ARTICLE 0 Reads 0 Citations Leidenfrost Rotor Dynamics: Design of Turbine-inspired Substrates Prashant Agrawal, Gary G. Wells, Rodrigo Ledesma-Aguilar, Gl... Published: 01 April 2019
Proceedings of the 4th World Congress on Momentum, Heat and Mass Transfer, doi: 10.11159/enfht19.138
DOI See at publisher website
Article 0 Reads 0 Citations Leidenfrost heat engine: Sustained rotation of levitating rotors on turbine-inspired substrates Prashant Agrawal, Gary G. Wells, Rodrigo Ledesma-Aguilar, Gl... Published: 01 April 2019
Applied Energy, doi: 10.1016/j.apenergy.2019.02.034
DOI See at publisher website ABS Show/hide abstract
The prospect of thermal energy harvesting in extreme environments, such as in space or at microscales, offers unique opportunities and challenges for the development of alternate energy conversion technologies. At microscales mechanical friction presents a challenge in the form of energy losses and wear, while presence of high temperature differences and locally available resources inspire the development of new types of heat engines for space and planetary exploration. Recently, levitation using thin-film boiling, via the Leidenfrost effect, has been explored to convert thermal energy to mechanical motion, establishing the basis for novel reduced-friction heat engines. In the Leidenfrost effect, instantaneous thin-film boiling occurs between a droplet and a heated surface, thereby levitating the droplet on its own vapor. This droplet state provides virtually frictionless motion and self-propulsion, whose direction can be designed into the system by asymmetrically texturing the substrate. However, sustaining such thermal to mechanical energy conversion is challenging because the Leidenfrost transition temperature for water on a smooth metal surface is ∼220 °C and, despite the low thermal conductivity of the vapor layer, the droplet continuously evaporates. Further challenges include effective transfer of thermal energy into rotational, rather than linear motion, and driving solid components and not simply droplets. Here we present a Leidenfrost rotor, where a solid component is coupled to a rotating liquid volume using surface tension and levitated in continuous operation over a turbine-inspired substrate. We address two key challenges: we show how the liquid can be replenished to achieve the continuous operation of the device; and we show how a superhydrophobic coating to the substrate can broaden the temperature range of operation and the stability of the rotor. Because the liquid acts as a working substance by extracting heat from the substrate to produce useful work in the form of rotation of the coupled solid component, our results demonstrate that a Leidenfrost engine operating in a closed thermodynamic cycle is possible.
Article 0 Reads 0 Citations Apparent Contact Angles on Lubricant-Impregnated Surfaces/SLIPS: From Superhydrophobicity to Electrowetting. Glen McHale, Bethany V. Orme, Gary George Wells, Rodrigo And... Published: 05 March 2019
Langmuir, doi: 10.1021/acs.langmuir.8b04136
DOI See at publisher website PubMed View at PubMed
Article 0 Reads 0 Citations Pinning-Free Evaporation of Sessile Droplets of Water from Solid Surfaces Steven Armstrong, Glen McHale, Rodrigo Andres Ledesma-Aguila... Published: 31 January 2019
Langmuir, doi: 10.1021/acs.langmuir.8b03849
DOI See at publisher website
Article 0 Reads 1 Citation Dielectrowetting: The past, present and future A.M.J. Edwards, C.V. Brown, M.I. Newton, G. McHale Published: 01 July 2018
Current Opinion in Colloid & Interface Science, doi: 10.1016/j.cocis.2017.11.005
DOI See at publisher website ABS Show/hide abstract
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 R. Tao, S. A. Hasan, H. Z. Wang, J. Zhou, J. T. Luo, G. McHa... Published: 13 June 2018
Scientific Reports, doi: 10.1038/s41598-018-27324-1
DOI See at publisher website PubMed View at PubMed ABS Show/hide abstract
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.