PROJECT TITLE :

Interrogation of Droplet Configuration During Electrowetting via Impedance Spectroscopy

ABSTRACT:

Several parameters associated with the configuration of a microliter aqueous droplet are determined by the electrical impedance measurements conducted throughout electrowetting. In each case, the wetted area of a dielectric-coated electrode is initial determined from the impedance information, and the known dielectric thickness and permittivity. The wetted space knowledge is then used in an exceedingly series of identification problems. In the best of these, we tend to demonstrate that the contact angle will be accurately found as a operate of applied bias voltage. Therefore, the Lippmann–Young (LY) curve of an electrowetting system can be determined from the impedance information alone while not the use of any optical measurements. In another take a look at, we show that the degree of a microliter droplet can be estimated from electrical impedance measurements with an error of <1%. A similar algorithm was used to determine the surface tension of the interface between the droplet and the encircling oil to an accuracy of 4%. In still another identification experiment, the impedance information from multiple bias voltages were used as a batch to spot several unknown configuration parameters simultaneously (volume, interfacial tension, and 0-voltage contact angle). It is shown that identification accuracy is degraded in this case, because there exists a direction among the parameter house of low error sensitivity. Determining multiple parameters along, thus, needs that the perfect LY relation fits the electrowetting behavior well over the vary of voltages utilized and that the dielectric parameters are accurately known. [2015-013three]