An engineered anisotropic nanofilm with unidirectional wetting properties

Niranjan A. Malvadkar, Matthew J. Hancock, Koray Sekeroglu, Walter J. Dressick, Melik C. Demirel

Research output: Contribution to journalArticlepeer-review

392 Scopus citations


Anisotropic textured surfaces allow water striders to walk on water, butterflies to shed water from their wings and plants to trap insects and pollen. Capturing these natural features in biomimetic surfaces is an active area of research. Here, we report an engineered nanofilm, composed of an array of poly(p-xylylene) nanorods, which demonstrates anisotropic wetting behaviour by means of a pin-release droplet ratchet mechanism. Droplet retention forces in the pin and release directions differ by up to 80 μN, which is over ten times greater than the values reported for other engineered anisotropic surfaces. The nanofilm provides a microscale smooth surface on which to transport microlitre droplets, and is also relatively easy to synthesize by a bottom-up vapour-phase technique. An accompanying comprehensive model successfully describes the filmĝ€™s anisotropic wetting behaviour as a function of measurable film morphology parameters.

Original languageEnglish (US)
Pages (from-to)1023-1028
Number of pages6
JournalNature Materials
Issue number12
StatePublished - Dec 2010

All Science Journal Classification (ASJC) codes

  • General Chemistry
  • General Materials Science
  • Condensed Matter Physics
  • Mechanics of Materials
  • Mechanical Engineering


Dive into the research topics of 'An engineered anisotropic nanofilm with unidirectional wetting properties'. Together they form a unique fingerprint.

Cite this