Microsystem Technologies

, Volume 19, Issue 2, pp 245–251 | Cite as

Light-actuated water droplet motions on ZnO nanorods

  • Chien-Wei Liu
  • Chen-Pin Hsu
  • J. Andrew Yeh
  • Yuh-Chang Sun
  • Yu-Fen Huang
  • Byung Hwan Chu
  • Fan Ren
  • Yu-Lin WangEmail author
Technical Paper


Water droplets were either pushed or pulled with an ultra-violet (UV) light on vertically aligned ZnO nanorods. Steric acid-immobilized ZnO nanorods grown on quartz substrates exhibit a hydrophobic surface possessing high contact angles between water droplets and the substrates. Exposure of UV onto droplets on ZnO NRs led to reduction of contact angles and resulted the internal circulating flows inside the droplets. Droplets located at different sites under the spot of the UV light created different magnitudes of contact angle changes and the internal circulating flows which allowed us to push the droplets away or pull the droplets toward the centre of the UV spot.


Contact Angle Water Droplet Quartz Substrate Internal Flow Superhydrophobic Surface 
These keywords were added by machine and not by the authors. This process is experimental and the keywords may be updated as the learning algorithm improves.



This work was partially supported by National Science Council grant (No. 99B20495A) and by the research grant (100N2049E1) at National Tsing Hua University.

Supplementary material

Supplementary material 1 (MPG 6338 kb)

Supplementary material 2 (WMV 7869 kb)

Supplementary material 3 (MPG 10676 kb)


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Copyright information

© Springer-Verlag 2012

Authors and Affiliations

  • Chien-Wei Liu
    • 1
  • Chen-Pin Hsu
    • 1
  • J. Andrew Yeh
    • 1
  • Yuh-Chang Sun
    • 2
  • Yu-Fen Huang
    • 2
  • Byung Hwan Chu
    • 3
  • Fan Ren
    • 3
  • Yu-Lin Wang
    • 1
    Email author
  1. 1.Institute of Nanoengineering and MicrosystemsNational Tsing Hua UniversityHsinchuTaiwan
  2. 2.Department of Biomedical Engineering and Environmental SciencesNational Tsing Hua UniversityHsinchuTaiwan
  3. 3.Department of Chemical EngineeringUniversity of FloridaGainesvilleUSA

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