Aerial wetting contact angle measurement using confocal microscopy

Jacob W. Chesna, Bob F. Wiedmaier, Jinlin Wang, Ayman Samara, Richard K. Leach, Tsing Hua Her, Stuart T. Smith

Research output: Contribution to journalArticle

2 Citations (Scopus)


A method is presented in which the wetting contact angle of a sessile drop is acquired aerially using confocal techniques to measure the radius and the height of a droplet deposited on a planar surface. The repeatability of this method is typically less than 0.25°, and often less than 0.1°, for droplet diameters less than 1 mm. To evaluate accuracy of this method, an instrument uncertainty budget is developed, which predicts a combined uncertainty of 0.91° for a 1 mm diameter water droplet with a contact angle of 110°. For droplets having diameters less than 1 mm and contact angles between 15° and 160°, these droplets approach spherical shape and their contact angles can be computed analytically with less than 1% error. For larger droplets, gravitational deformation needs to be considered.

Original languageEnglish
Article number125202
JournalMeasurement Science and Technology
Issue number12
Publication statusPublished - 26 Oct 2016



  • confocal microscopy
  • contact angle
  • wettability

ASJC Scopus subject areas

  • Instrumentation
  • Applied Mathematics

Cite this

Chesna, J. W., Wiedmaier, B. F., Wang, J., Samara, A., Leach, R. K., Her, T. H., & Smith, S. T. (2016). Aerial wetting contact angle measurement using confocal microscopy. Measurement Science and Technology, 27(12), [125202].