Room-temperature fabrication of anodic tantalum pentoxide for low-voltage electrowetting on dielectric (EWOD)

Li, Yifan, Parkes, William, Haworth, Les, Ross, A., Stevenson, J. and Walton, Anthony (2008) Room-temperature fabrication of anodic tantalum pentoxide for low-voltage electrowetting on dielectric (EWOD). Journal of Microelectromechanical Systems, 17 (6). pp. 1481-1488. ISSN 1057-7157

Full text not available from this repository. (Request a copy)

Abstract

This paper presents a robust anodic Ta2O5 dielectric as an alternative insulator for fabricating low-voltage electrowetting on dielectric (EWOD) systems. Previously reported low-voltage EWOD technologies require high-temperature processes ( > 435degC), which unlike this room temperature technology, are not compatible with standard copper and aluminum integrated circuit interconnect technology as well as polymer-based substrates. The anodized Ta2O5 forms a uniform pinhole free layer with a surface roughness (R a) of 0.6 nm. This robust film enables an ultrathin amorphous FluoroPolymer layer to be employed to reduce the EWOD driving voltage to 13 V. Both sub-20-nm Teflon-AF and CYTOP layers have been successfully coated on top of Ta2O5 with good adhesion. Applying voltages of 6-15 V significantly modified the contact angles of droplets in air on these samples (121deg to 81deg on Teflon-AF at 13 V and 114deg to 95deg on CYTOP at 6 V). Successful 14-V EWOD manipulation involving droplets being dispensed from a reservoir, their movement, followed by merging them together has been demonstrated using devices using a Teflon-AF + Ta2O5 dielectric.

Item Type:	Article
Uncontrolled Keywords:	Amorphous FluoroPolymer (aFP), CMOS, electrowetting on dielectric (EWOD), microfluidics
Subjects:	F200 Materials Science F300 Physics H600 Electronic and Electrical Engineering
Department:	Faculties > Engineering and Environment > Mechanical and Construction Engineering
Depositing User:	Yifan Li
Date Deposited:	26 Feb 2015 13:50
Last Modified:	13 Oct 2019 00:20
URI:	http://nrl.northumbria.ac.uk/id/eprint/21219

Downloads