This work has shown a novel method for the separation of particles inside a nonlinear EK device using low frequency cyclical signals. The utility of this method was demonstrated by successfully separating micron sized polystyrene particles based on differences in particle size (2 Β΅m vs. 5.1 Β΅m) and by differences in particle charge (19 vs. 60 mv). In order to discover a usable signal for separation, a custom Matlab program was developed to simulate particle migration inside the device. The custom program utilized data from finite element analysis of the electric field in the device using the COMSOL Multiphysics program. After successfully separating particle using this method, it was discovered that the more likely force present in the system was not DEP, as was previously assumed, but rather nonlinear electrophoresis. The knowledge of this phenomena was implemented into the custom Matlab program. However, the method previously created for determining πœ‡π·πΈπ‘ƒ was not usable for the determination of πœ‡πΈπ‘ƒ (3) . In light of this, the second part of this study was preformed to determine a useable method for determining πœ‡πΈπ‘ƒ (3) . Three methods were developed and tested on one particle type. The best method from these three methods were selected and used for the determination of πœ‡πΈπ‘ƒ (3) for four distinct particle types. These πœ‡πΈπ‘ƒ (3) values were then compared to πœ‡πΈπ‘ƒ (3) values derived from the latest model for nonlinear EP in systems similar to those used in this study [1]. The methodology developed in this work could have applications in the development of methods and devices which could separate micron-sized bioparticles such as yeast and bacteria.

Library of Congress Subject Headings

Electrokinetics; Electrophoresis

Publication Date


Document Type


Student Type


Degree Name

Mechanical Engineering (MS)

Department, Program, or Center

Mechanical Engineering (KGCOE)


Blanca Lapizco-Encinas

Advisor/Committee Member

Michael Schertzer

Advisor/Committee Member

Michael Schrlau


RIT – Main Campus

Plan Codes