Dhindsa Manjeet S, Smith Neil R, Heikenfeld Jason, Rack Philip D, Fowlkes Jason D, Doktycz Mitchel J, Melechko Anatoli V, Simpson Michael L
Novel Devices Laboratory, University of Cincinnati, Cincinnati, Ohio 45220, USA.
Langmuir. 2006 Oct 10;22(21):9030-4. doi: 10.1021/la061139b.
Reversible electrostatically induced wetting (electrowetting) of vertically aligned superhydrophobic carbon nanofibers has been investigated. Carbon nanofibers on a 5 x 5 microm pitch were grown on Si substrates, electrically insulated with a conformal dielectric, and hydrophobized with fluoropolymer. This nanostructured scaffold exhibited superhydrophobic behavior for saline (theta approximately 160 degrees). Electrowetting induced a contact angle reduction to theta approximately 100 degrees. Competitive two-liquid (dodecane/saline) electrowetting exhibited reversibility on the same nanostructured scaffold. Without applied bias, ultra-fine-point tip (approximately 25 nm radius) nanofibers result in effectively zero capacitance with the overlying saline layer. Complete electrowetting of the substrate is confirmed as capacitance values increase by several orders of magnitude with increased wetting. These results demonstrate the applicability of reversible electrowetting on nanostructured scaffolds and use of nanofabricated structures that can be integrated with various micro- and nanoelectronic technologies.
已对垂直排列的超疏水碳纳米纤维的可逆静电诱导润湿（电润湿）进行了研究。在硅衬底上生长了间距为5×5微米的碳纳米纤维，用保形电介质进行电绝缘，并用含氟聚合物进行疏水化处理。这种纳米结构支架对盐水表现出超疏水行为（接触角约为160度）。电润湿使接触角减小到约100度。竞争性双液（十二烷/盐水）电润湿在同一纳米结构支架上表现出可逆性。在未施加偏压时，超细尖端（半径约25纳米）的纳米纤维与覆盖的盐水层之间的电容实际上为零。随着润湿性增加，电容值增加几个数量级，证实了衬底的完全电润湿。这些结果证明了可逆电润湿在纳米结构支架上的适用性，以及可与各种微纳电子技术集成的纳米制造结构的应用。
