Frequency-based relationship of electrowetting and dielectrophoretic liquid microactuation

Langmuir

Volumn 19, Issue 18, 2003, Pages 7646-7651

  Jones, T B ^a   Fowler, Jesse David ^b   Chang, Young Soo ^c   Kim, Chang Jin ^b  

^a University of Rochester   (United States)

^b UNIVERSITY OF CALIFORNIA   (United States)

^c Korea Institute of Science and Technology   (South Korea)

Author keywords

[No Author keywords available]

Indexed keywords

DROP FORMATION; ELECTRIC FIELD EFFECTS; ELECTROCHEMICAL ELECTRODES; ELECTROPHORESIS; INSULATING OIL; MATHEMATICAL MODELS; PERMITTIVITY; PRESSURE EFFECTS; SOLUBILITY; WETTING;

DIELECTROPHORETIC LIQUID MICROACTUATION; ELECTRIC FIELD INDUCED PRESSURE CHANGE; ELECTROWETTING; MAXWELL STRESS TENSOR;

DIELECTRIC LIQUIDS;

EID: 0141830020     PISSN: 07437463     EISSN: None     Source Type: Journal    
DOI: 10.1021/la0347511     Document Type: Article

References (26)

1. Lee, J.; Moon, H.; Fowler, J.; Schoellhammer, T.; Kim, C.-J. Electrowetting and electrowetting-on-dielectric for microscale liquid handling. Sens. Actuators 2002, A95, 259-268.
2. Pollack, M. G.; Fair, R. B.; Shenderov, A. D. Electrowetting-based actuation of liquid droplets for microfluidic actuation. Appl. Phys. Lett. 2000, 77, 1725-1726.
3. Moon, H.; Cho, S. K.; Garrell, R. L.; Kim, C.-J. Low voltage electrowetting-on-dielectric. J. Appl. Phys. 2002, 92, 4080-4087.
4. Jones, T. B.; Gunji, M.; Washizu, M. Dielectrophoretic liquid actuation and nanodroplet formation. J. Appl. Phys. 2001, 89, 1441-1448.
5. Ahmed, R.; Hsu, D.; Bailey, C.; Jones, T. B. Dispensing picoliter droplets using DEP micro-actuation. Microchannels and Minichannels Conference (ASME), Rochester, NY, April, 2003.
6. Gunji, M.; Jones, T. B.; Washizu, M. DEP-driven simultaneous 2 × 2 droplet array mixer. μTAS 2002 Proceedings 2002, 2, 721-723.
7. Gunji, M.; Washizu, M. Liquid DEP droplet actuator and mixer on a heat-conducting substrate. Annual IEEE/IAS Conference, Little Rock, AR, June, 2003.
8. Quincke, G. Electrische Untersuchungen. Ann. Phys. Chem., 3rd Ser. (Leipzig) 1883, 255, 705-782.
9. Pickard, W. F. Electrical force effects in dielectric liquids. Prog. Dielectr. 1965, 6, 1-39.
10. Landau, L. D.; Lifshitz, E. M. Electrodynamics of continuous media; Pergamon: Oxford, 1960; Section 15.
11. Woodson, H. H.; Melcher, J. R. Electromechanical dynamics, part I: Discrete systems; Wiley: New York, 1968; Chapter 7.
12. Melcher, J. R. A tutorial on induced electrohydrodynamic forces. MIT, unpublished, ca. 1968 (available by request from the authors).
13. Rosenkilde, C. E. A dielectric fluid drop in an electric field. Proc. Royal Soc. (London) 1969, A312, 473-494.
14. The ponderomotive term of the Korteweg-Helmholtz body force density might seem to be nonphysical, as there is no obvious mechanism for a dipole force at a boundary when no electric field gradient exists; however, the proper usage of eq 1 is only to calculate the total force on a ponderable body by an appropriate volume integral or by a surface integral of the Maxwell stress tensor. Attaching physical significance to the point-by-point distribution of a body force formulation is not always meaningful and anyway unnecessary.
15. Jones, T. B. On the relationship of dielectrophoresis and electrowetting. Langmuir 2002, 18, 4437-4443.
16. e is based on an energy argument and, as such, accounts completely for all electrical contributions to the measured pressure change. It is thus incorrect to include an additional term based on the change in the contact angle caused by the electric field because to do so would be double-counting.
17. Shapiro, B.; Moon, H.; Garrell, R.; Kim, C.-J. Equilibrium behavior of sessile droplets under surface tension, applied external fields, and material variations. J. Appl. Phys. 2003, 93, 5794-5811.
18. Welters, W. J. J.; Fokkink, L. G. J. Fast electrically switchable capillary effects. Langmuir 1998, 14, 1535-1538.
19. Kang, K. H.; Kang, I. S.; Lee, C. M. Wetting tension due to Coulombic interaction in charge-related wetting phenomena. Langmuir 2002, 18, 10318-10322.
20. Experimentation with ionic salt solutions (e.g., KCl) would introduce the possibility of adjusting the electrical conductivity in a controlled fashion. Such experiments are ultimately of great interest, and we plan to pursue them. But working with salt solutions adds the major complication of having to worry about electrolysis and salt buildup on the coated electrodes, which could damage the dielectric coatings. For the purpose of showing the frequency-dependent relationship of DEP and EWOD, we elected to fix the conductivity and vary the frequency.
21. Vallet, M.; Vallade, M.; Berge, B. Limiting phenomena for the spreading of water on polymer films by electrowetting. Eur. Phys. J. 1999, B11, 583-591.
22. Vallet, M.; Berge, B.; Vovelle, L. Electrowetting of water and aqueous solutions on poly(ethylene terephthalate) insulating films. Polymer 1996, 37, 2465-2470.
23. Mugele, F.; Herminghaus, S. Electrostatic stabilization of fluid microstructures. Appl. Phys. Lett. 2002, 81, 2303-2305.
24. Berge, B. Electrocapillarité et mouillage de films isolants par l'eau. C. R. Acad. Sci., Ser. II 1993, 317, 157-163.
25. Janocka, B.; Bauser, H.; Oehr, C.; Brunner, H.; Göpel, W. Competitive electrowetting of polymer surfaces by water and decane. Langmuir 2000, 16, 3349-3354.
26. Blake, T. D.; Clarke, A.; Stattersfield, E. H. An investigation of electrostatic assist in dynamic wetting. Langmuir 2000, 16, 2928-2935.