DocumentCode :
3332219
Title :
Modeling of electrowetted surface tension for addressable microfluidic systems: dominant physical effects, material dependences, and limiting phenomena
Author :
Shapiro, Benjamin ; Moon, Hyejin ; Garrell, Robin ; Kim, Chang-Jin
Author_Institution :
Maryland Univ., College Park, MD, USA
fYear :
2003
fDate :
19-23 Jan. 2003
Firstpage :
201
Lastpage :
205
Abstract :
This paper describes the equilibrium shape of a liquid drop under applied fields such as gravity and electrical fields, taking into account material properties such as dielectric constants, resistivities, and surface tension coefficients. The analysis is based on an energy minimization framework, scaling arguments, and on solutions of Maxwell´s electrostatic equations. A rigorous and exact link is provided between the energy function corresponding to any given physical phenomena, and the resulting shape and size dependent force term in the (modified) Young´s equation. It is shown that a dielectric solid and a perfectly conducting liquid is all that is needed to exactly recover the Young-Lippmann equation. A dielectric liquid on a conducting solid gives rise to line tension terms. Finally, a slightly resistive liquid on top of a dielectric, highly resistive solid gives rise to contact angle saturation and accurately predicts the experimental data that we observe in our electrowetting devices.
Keywords :
contact angle; drops; electrohydrodynamics; microfluidics; surface tension; wetting; Maxwell electrostatic equations; Young equation; Young-Lippmann equation; addressable microfluidic systems; conducting solid; contact angle saturation; dielectric liquid; dielectric solid; electrowetted surface tension; energy minimization; equilibrium liquid drop shape; limiting phenomena; line tension terms; material properties; modeling; perfectly conducting liquid; scaling arguments; Dielectric constant; Dielectric liquids; Dielectric materials; Gravity; Material properties; Maxwell equations; Microfluidics; Shape; Solids; Surface tension;
fLanguage :
English
Publisher :
ieee
Conference_Titel :
Micro Electro Mechanical Systems, 2003. MEMS-03 Kyoto. IEEE The Sixteenth Annual International Conference on
ISSN :
1084-6999
Print_ISBN :
0-7803-7744-3
Type :
conf
DOI :
10.1109/MEMSYS.2003.1189721
Filename :
1189721
Link To Document :
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