title: Cantilever bending based on humidity-actuated mesoporous silica/silicon bilayers.
abstract: We use a soft templating approach in combination with evaporation induced self-assembly to prepare mesoporous films containing cylindrical pores with elliptical cross-section on an ordered pore lattice. The film is deposited on silicon-based commercial atomic force microscope (AFM) cantilevers using dip coating. This bilayer cantilever is mounted in a humidity controlled AFM, and its deflection is measured as a function of relative humidity. We also investigate a similar film on bulk silicon substrate using grazing-incidence small-angle X-ray scattering (GISAXS), in order to determine nanostructural parameters of the film as well as the water-sorption-induced deformation of the ordered mesopore lattice. The strain of the mesoporous layer is related to the cantilever deflection using simple bilayer bending theory. We also develop a simple quantitative model for cantilever deflection which only requires cantilever geometry and nanostructural parameters of the porous layer as input parameters.
authors.affiliation: Institute of Physics, Montanuniversitaet Leoben, Austria.
authors.forename: Christian
authors.initials: C
authors.lastname: Ganser
authors.affiliation: Institute of Physics, Montanuniversitaet Leoben, Austria.
authors.forename: Gerhard
authors.initials: G
authors.lastname: Fritz-Popovski
authors.affiliation: Institute of Physics, Montanuniversitaet Leoben, Austria.
authors.forename: Roland
authors.initials: R
authors.lastname: Morak
authors.affiliation: Institute of Physics, Montanuniversitaet Leoben, Austria; Max-Planck-Institut für Kohlenforschung, Mülheim an der Ruhr, Germany.
authors.forename: Parvin
authors.initials: P
authors.lastname: Sharifi
authors.affiliation: Institute of Inorganic Chemistry, Graz University of Technology, Austria.
authors.forename: Benedetta
authors.initials: B
authors.lastname: Marmiroli
authors.affiliation: Institute of Inorganic Chemistry, Graz University of Technology, Austria.
authors.forename: Barbara
authors.initials: B
authors.lastname: Sartori
authors.affiliation: Institute of Inorganic Chemistry, Graz University of Technology, Austria.
authors.forename: Heinz
authors.initials: H
authors.lastname: Amenitsch
authors.affiliation: Chair of Chemistry of Polymeric Materials, Montanuniversitaet Leoben, Austria.
authors.forename: Thomas
authors.initials: T
authors.lastname: Griesser
authors.affiliation: Institute of Physics, Montanuniversitaet Leoben, Austria.
authors.forename: Christian
authors.initials: C
authors.lastname: Teichert
authors.affiliation: Institute of Physics, Montanuniversitaet Leoben, Austria.
authors.forename: Oskar
authors.initials: O
authors.lastname: Paris
keywords: AFM cantilever; bilayer bending; grazing incidence small-angle X-ray scattering (GISAXS); mesoporous film; sorption-induced deformation