AVS 49th International Symposium
    Surface Science Thursday Sessions
       Session SS-ThA

Paper SS-ThA8
Adhesion Sensor: Non-Contact AFM for Quantitative Adhesion Measurements

Thursday, November 7, 2002, 4:20 pm, Room C-110

Session: Tribology at Surfaces
Presenter: A. Schirmeisen, University of Muenster, Germany
Authors: A. Schirmeisen, University of Muenster, Germany
D. Weiner, University of Muenster, Germany
H. Fuchs, University of Muenster, Germany
Correspondent: Click to Email
The adhesion characteristics of metal coatings on Polycarbonate are of high technological interest. For example, Aluminum is used to coat plastic surfaces, with a wide range of applications. However, adhesion failure of metal coatings on polycarbonat is often observed. Methods such as flame annealing@footnote 1@ or plasma treatment@footnote 2@ are typically employed to improve adhesion characteristics. Yet little is known of the microscopic processes leading to the modified surface properties. We can quantify the adhesion properties of Al on differently treated polymers using dynamic AFM. Conventionally, adhesion tests are performed using a tape puller or similar device. The sample is usually destroyed after the test and no lateral resolution of the adhesion properties is achieved. In a novel approach using NC-AFM we can quantify the adhesion characteristics of the polymer-metal interface with nm-resolution. We measure frequency shift versus distance curves of a functionalised NC-AFM cantilever on the polymer surface. A specially designed UHV apparatus allows the in-situ preparation of tip and sample and the investigation of the interfacial force interactions with a UHV-AFM. The tip is functionalised by evaporation of a thin Al film on the cantilever. The adhesion properties of the polymer are modified by plasma treatment. Measurements of frequency shift versus tip-sample distance reveal the influence of the sample treatment on the adhesion properties. Following the approach of Durig,@footnote 3@ we calculate force curves from the frequency shift data,@footnote 4@ and extract quantitative values for the interfacial adhesion energy. @FootnoteText@ @footnote 1@ A.P.Pijpers, R.J. Meier, J. Electron Spectr. 121 (2001) 299@footnote 2@ C. Seidel, H. Kopf, B.Gotsmann, T. Vieth, H. Fuchs, K. Reihs, Appl. Surf. Sci. 150 (1999) 19@footnote 3@ U. Durig, Appl. Phys. Lett. 75 (1999) 433@footnote 4@ Calculation based on programm from H. Holscher, CAESAR Institute, Germany.