Aerial wetting contact angle measurement using confocal microscopy

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

Abstract

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.

Citation

Chesna, J. W., Wiedmaier, B. F., Wang, J., Samara, A., Leach, R. K., Her, T., & Smith, S. T. (in press). Aerial wetting contact angle measurement using confocal microscopy. Measurement Science and Technology, 27(12), https://doi.org/10.1088/0957-0233/27/12/125202

• Journal Article Type: Article
• Acceptance Date: Sep 16, 2016
• Online Publication Date: Oct 26, 2016
• Deposit Date: Oct 28, 2016
• Publicly Available Date: Oct 28, 2016
• Journal: Measurement Science and Technology
• Print ISSN: 0957-0233
• Electronic ISSN: 1361-6501
• Publisher: IOP Publishing
• Peer Reviewed: Peer Reviewed
• Volume: 27
• Issue: 12
• DOI: https://doi.org/10.1088/0957-0233/27/12/125202
• Public URL: https://nottingham-repository.worktribe.com/output/821456
• Publisher URL: http://iopscience.iop.org/article/10.1088/0957-0233/27/12/125202/meta