Electromechanics of dielectric particles in dielectric liquids acted on by a microelectrode array
Arrays of microelectrodes were used to apply forces to dielectric (soda lime glass)
spheres in a thin (200 micrometer thick) layer of a dielectric liquid polymer (EOPN
8021). The microelectrodes were fabricated using standard photolithographic methods of
evaporating and electroplating gold onto a glass substrate. The objective is to use the
electric body forces in the sphere and the electric surface tractions on the sphere to
position the spheres in a microscale pattern, in this case a square array in-plane.
Three sizes of spheres were used: 30, 90, and 170 microns in diameter. The 30
micron spheres formed clusters associated with the regions of highest electric energy
density, whereas single 90 micron spheres were located at the regions of highest electric
energy density. The 170 micron spheres generally did not form patterns. The
experiments indicated that free charges, either in the volume of the sphere and/or on the
sphere surface, significantly influence the motion of the sphere.
A finite element analysis was performed to study the electro-fluid mechanics.
The liquid velocity and streamlines were plotted, and the force resultants due to the
liquid acting on the sphere were calculated. Also, the electric body force and surface tractions resultants were calculated. In general, the forces on the sphere and the liquid
velocity are in agreement with the experimental results.
Advisor:Boyd, James G.; Kim, Won-jong; Lagoudas, Dimitris C.; Whitcomb, John D.
School:Texas A&M University
School Location:USA - Texas
Source Type:Master's Thesis
Keywords:dielectrophresis composite materials electromechanics electrofluid mechanics
Date of Publication:12/01/2005