SAMPARA, N., 2013. Voltage induced spreading and liquid optical devices. PhD, Nottingham Trent University.
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An experimental investigation has been carried out into Liquid dielectrophoresis (LDEP), in which dielectric forces are used to actuate bulk liquid spreading and to imprint a deformation pattern at a liquid air surface. Our basic conguration uses a set of co-planar stripe interdigital electrodes to create a non-uniform A.C. electric field that exponentially decays in amplitude and penetrates above the structure into a dielectric liquid droplet. Dielectric forces drive a voltage-induced spreading of the droplet into a low contact angle droplet/film, an effect which will be referred to here as "dielectrowetting". Further application of the A.C. voltage to the electrodes results in a static sinusoidal wrinkle forming at the oil-air interface on the spread film. Three main areas of investigations are reported, the first of which is a study of the statics and dynamics of the voltage induced spreading of a stripe of the material 1,2 propylene glycol. In the limit of thick droplets, a theoretical prediction has been derived that the cosine of the static equilibrium contact angle is proportional to the square of the amplitude of the voltage applied to the inter-digital electrodes. This relationship is analogous to that found for electrowetting-on-dielectric (EWOD). Experimental observations confirm this predicted dielectrowetting behavior for the advancing static contact angle of the voltage induced spreading of a stripe of the material 1,2 propylene glycol.
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|Divisions:||Schools > School of Science and Technology|
|Depositing User:||EPrints Services|
|Date Added:||09 Oct 2015 09:33|
|Last Modified:||09 Oct 2015 09:33|
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