A simple atomic force microscopy calibration method for direct measurement of surface energy on nanostructured surfaces covered with molecularly thin liquid films

• Published in: Review of scientific instruments Vol. 80; no. 5; p. 055109
• Main Authors: Brunner, Ralf, Etsion, Izhak, Talke, Frank E
• Format: Journal Article
• Language: English
• Published: United States 01.05.2009
• Subjects: Calibration; Lubricants; Microscopy, Atomic Force - methods; Microscopy, Atomic Force - standards; Nanostructures - chemistry; Surface Properties
• ISSN: 1089-7623
• DOI: 10.1063/1.3136908

A simple calibration method is described for the determination of surface energy by atomic force microscopy (AFM) pull-off force measurements on nanostructured surfaces covered with molecularly thin liquid films. The method is based on correlating pull-off forces measured in arbitrary units on a nanostructured surface with pull-off forces measured on macroscopically smooth dip-coated gauge surfaces with known surface energy. The method avoids the need for complex calibration of the AFM cantilever stiffness and the determination of the radius of curvature of the AFM tip. Both of the latter measurements are associated with indirect and less accurate measurements of surface energy based on various contact mechanics adhesion models.