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Access Type

WSU Access

Date of Award

January 2012

Degree Type


Degree Name



Electrical and Computer Engineering

First Advisor

Amar S. Basu






Ankur Doshi

January, 2012

Advisor: Dr. Amar Basu

Major: Electrical Engineering

Degree: Master of Science

One of the most vital resources for human life is fresh water. Only 10 million of

1400 million cubic meters of water on the planet is of low salinity which is suitable for

use after applying conventional water treatment techniques. The growing demand and

an increasing depletion of fresh water have necessitated development of various

technologies to tap this resource. Desalination has been one of the most attractive

techniques to overcome this predicament. The other standard approaches includes,

reverse osmosis and electrodialysis. However, these techniques are extremely

expensive. Hence small scale portable desalination systems providing high throughput

while utilizing minimum power are highly desirable. Here, we demonstrate a novel

technique of separating charged ions which can potentially be used towards

desalination of water.

A simple microfluidic device was designed and used for separating two synthetic

dyes (fluorescein and umbelliferone) with an electric field of 51V/cm depending on their

electrophoretic charges. The separated ions were distinguished based on their

fluorescence emission band. Power consumed by a single unit was measured in the

range of 1.78 - 2.3 mW at a flow rate of 10L/min. Due to its low power consumption

and membrane-less approach, in future, this process can be compared to several other

established desalination techniques.