Measuring the adhesion strength of a thin film to a substrate by centrifugation

Abstract

This paper describes a centrifugation-based method of quantifying the adhesion strength of a thin film to a substrate. Normally thin films possess extremely small mass, and the centrifugal force cannot dislodge the thin films from the substrates even with the most powerful centrifuge. To solve this problem, we synthesized hydrogel particles on top of the thin film. The hydrogel particle was bound to the thin film through covalent bonds. The centrifugal force was therefore substantially increased, and the thin film could be dislodged from the substrate together with the hydrogel particles in a tabletop centrifuge. We validated this method by measuring the adhesion strength of adhesive tape to Teflon and compared it with the pull-off test result. We applied this method to measuring the adhesion strength of a polydopamine (PDA) thin film to Teflon, which has not yet been characterized. The measurement of the PDA adhesion strength would help in studying the mechanism of PDA adhesion and develop stronger PDA adhesive. The centrifugation-based method is simple and applicable to a broad range of thin films and substrates.