title: Nanomechanical properties of advanced plasma polymerized coatings for mechanical data storage.
abstract: In this paper we report on the unprecedented deformation behavior of stratified ultrathin polymer films. The mechanical behavior of layered nanoscale films composed of 8-12 nm thin plasma polymerized hexamethyldisiloxane (ppHMDSO) films on a 70 nm thick film of polystyrene was unveiled by atomic force microscopy nanoindentation. In particular, we observed transitions from the deformation of a thin plate under point load to an elastic contact of a paraboloid of revolution, followed by an elastic-plastic contact for polystyrene and finally an elastic contact for silicon. The different deformation modes were identified on the basis of force-penetration data and atomic force microscopy images of residual indents. A clear threshold was observed for the onset of plastic deformation of the films at loads larger than 2 μN. The measured force curves are in agreement with an elastic and elastic-plastic contact mechanics model, taking the amount of deformation and the geometry of the layer that presumably contributed more to the overall deformation into account. This study shows that the complex deformation behavior of advanced soft matter systems with nanoscale dimensions can be successfully unraveled.
authors.affiliation: Max Planck Institute for Polymer Research, Ackermannweg 10, 55128 Mainz, Germany.
authors.forename: Davide
authors.initials: D
authors.lastname: Tranchida
authors.forename: Sascha A
authors.initials: SA
authors.lastname: Pihan
authors.forename: Yi
authors.initials: Y
authors.lastname: Zhang
authors.forename: Holger
authors.initials: H
authors.lastname: Schönherr
authors.forename: Rüdiger
authors.initials: R
authors.lastname: Berger
mesh_terms: D016247:Information Storage and Retrieval; D018625:Microscopy, Atomic Force; D036103:Nanotechnology; D011137:Polystyrenes / Q000737:chemistry; D012833:Siloxanes / Q000737:chemistry
chemical_list: D011137:Polystyrenes; D012833:Siloxanes; C015917:hexamethyldisiloxane