International Journal of Precision Engineering and Manufacturing

Korean Society for Precision Engineering (한국정밀공학회)
권호 표지

Characteristics of Electrowetting of Self-assembled Monolayer and Z-Tetraol Film

  • Lin Li-Yu (Department of Mechanical Engineering, Yonsei University) ;
  • Noh Dong-Sun (Department of Mechanical Engineering, Yonsei University) ;
  • Kim Dae-Eun (Department of Mechanical Engineering, Yonsei University)
  • Published : 2006.07.01
Download PDF
⟨ Previous Next ⟩

Abstract

A study of electrowetting using an Octadecyltrichlorosilane (OTS) self-assembled monolayer (SAM) and Z- Tetraol 2000 perfluoropolyether lubricant as hydrophobic layers on Si and $SiO_2$ wafer was performed. The $SiO_2$ layer used as insulating layer was thermally grown on the silicon wafer to a thickness of 220-230 nm. The results demonstrated that the contact angle decreased from $100^{\circ}$ to $80^{\circ}$ at 28 V applied potential on $SiO_2$ wafer coated with OTS and the contact angle appeared to be reversible. However, the contact angle on the $SiO_2$ wafer coated with Z- Tetraol 2000 was not observable at 28 V applied potential. Furthermore, the contact angle on the Si wafer coated with OTS or Z- Tetraol 2000 appeared to be irreversible due to the generation of electrolysis in the droplet. It is concluded that it is feasible to use SAM as a hydrophobic layer in electrowetting applications.

Keywords

References

  1. Cho, S. K., Moon, H. J. and Kim, C. J., 'Creating, transporting, cutting, and merging liquid droplets by electrowetting-based acutuation for digital microfluidic circuits,' Journal of Microelectromechauical System, Vol. 12, pp. 70-80, 2003 https://doi.org/10.1109/JMEMS.2002.807467
  2. Moon, H. J., Cho, S. K., Garrell, R. L., and Kim, C. J., 'Low voltage electrowetting-on-dielectric, Journal of Applied Physics,' Vol. 92, pp.4080-4087, 2002 https://doi.org/10.1063/1.1504171
  3. Chang, Y. W. and Kwok, D. Y., 'Electrowetting on dielectric: A low voltage study on self-assembled monolayers and its wetting kinetics,' The 2004 International conference on MEMS, NANO and smart system (ICMEN'04)
  4. Yoon, J. Y. and Garrell, R. L., 'Preventing Biomolecular Adsorption in Electrowetting-Based Biofluidic Chips,' Analytical Chemistry, Vol. 75, pp. 5097-5102, 2003 https://doi.org/10.1021/ac0342673
  5. Verheijen, H. J. J. and Prins, M. W. J., 'Reversible Electrowetting and Trapping of Charge: Model and Experiments,' Langmuir, Vol. 15,pp.6616-6620, 1999 https://doi.org/10.1021/la990548n
  6. Digilov, R., 'Charge-induced modification of contact angle: The secondary electrocapillary effect,' Langmuir, Vol. 16, pp. 6719-6723, 2000 https://doi.org/10.1021/la991308a
  7. Sung, I. H., Yang, J. C., Kim, D. E. and Shin, B. S., 'Micro/nanotribological characteristics of self-assembled monolayer and its application in nano-structure fabrication,' Wear, Vol. 255, pp. 808-818, 2003 https://doi.org/10.1016/S0043-1648(03)00058-9
  8. Bhushan, B., Liu, H. W. and Hsu, S. M., 'Adhesion and Friction Studies of Silicon and Hydrophobic and Low Friction Films and Investigation of Scale Effects,' Journal of Tribology, Vol. 126, pp. 583-590, 2004 https://doi.org/10.1115/1.1739407
  9. Eapena, K. C., Pattona, S. T. and Zahinskib, J. S., 'Lubrication of microelectromechanical systems (MEMS) using bound and mobile phases of Fomblin Zdol,' Tribology Letters, Vol. 12, pp. 35-41, 2002 https://doi.org/10.1023/A:1013971321480
  10. Seyrat, E. and Hayes, R. A, 'Amorphous fluoropolymers as insulators for reversible low-voltage electrowetting,' Journal of Applied Physics, Vol. 90, pp. 1383-1386, 2001 https://doi.org/10.1063/1.1383583
  11. Bramwell, S. T., 'Ferroelectric ice,' Nature, Vol. 397, pp. 212-213, 1999 https://doi.org/10.1038/16594
  12. Vegiri, A. and Farantos, S. C., 'Classical dynamics of hydrogen bonded systems: Water clusters,' Journal of Chemical Physics, Vol. 98, pp.4059-4075, 1993 https://doi.org/10.1063/1.465042
  13. Chaplin, M. F., 'A proposal for the structuring of water,' Biophysical Chemistry, Vol. 83, pp. 211-221, 1999 https://doi.org/10.1016/S0301-4622(99)00142-8
  14. Vegiri, A. and Schevkunov, S. V., 'A molecular dynamics study of structural transitions in small water clusters in the presence of an external electric field,' Journal of Chemical Physics, Vol. 115, pp. 4175-4185, 2001 https://doi.org/10.1063/1.1388545
  15. Shevkunov, S. V. and Vegiri, A., 'Electric field induced transitions in water clusters,' Journal of Molecular Structure (Theochem), Vol. 593, pp. 19-32, 2002 https://doi.org/10.1016/S0166-1280(02)00111-2