Static and dynamic characterization of robust superhydrophobic surfaces built from nano-flowers on silicon micro-post arrays
KAUST Grant NumberSA-C0040/UK-C0016
Online Publication Date2010-09-01
Print Publication Date2010-10-01
Permanent link to this recordhttp://hdl.handle.net/10754/599725
MetadataShow full item record
AbstractSuperhydrophobic nano-flower surfaces were fabricated using MEMS technology and microwave plasma-enhanced chemical vapor deposition (MPCVD) of carbon nanotubes on silicon micro-post array surfaces. The nano-flower structures can be readily formed within 1-2 min on the micro-post arrays with the spacing ranging from 25 to 30 μm. The petals of the nano-flowers consisted of clusters of multi-wall carbon nanotubes. Patterned nano-flower structures were characterized using various microscopy techniques. After MPCVD, the apparent contact angle (160 ± 0.2°), abbreviated as ACA (defined as the measured angle between the apparent solid surface and the tangent to the liquid-fluid interface), of the nano-flower surfaces increased by 139% compared with that of the silicon micro-post arrays. The measured ACA of the nano-flower surface is consistent with the predicted ACA from a modified Cassie-Baxter equation. A high-speed CCD camera was used to study droplet impact dynamics on various micro/nanostructured surfaces. Both static testing (ACA and sliding angle) and droplet impact dynamics demonstrated that, among seven different micro/nanostructured surfaces, the nano-flower surfaces are the most robust superhydrophobic surfaces. © 2010 IOP Publishing Ltd.
CitationChen L, Xiao Z, Chan PCH, Lee Y-K (2010) Static and dynamic characterization of robust superhydrophobic surfaces built from nano-flowers on silicon micro-post arrays. Journal of Micromechanics and Microengineering 20: 105001. Available: http://dx.doi.org/10.1088/0960-1317/20/10/105001.
SponsorsThe authors would like to express the sincerest gratitude to Professor Robert H Austin from Princeton University for his helpful discussion and suggestions. They acknowledge Professor Tong-Xi Yu's Impact Dynamics Laboratory for providing the high-speed CCD camera for the study of droplet impact dynamics. They are also grateful to Dr Hongkai Wu for the silanization treatment of the silicon substrate and micro-post array surfaces, and the staff at the Nanoelectronic Fabrication Facility and the Material Characterization and Preparation Facility. The research was partially supported by a grant from Hong Kong Research Grants Council (ref no. 615907) and partially supported by a grant from King Abdullah University of Science and Technology (KAUST award no. SA-C0040/UK-C0016).