title: Freestanding membranes of cross-linked gold nanoparticles: novel functional materials for electrostatic actuators.
abstract: Their tunable electrical, optical, and mechanical properties make freestanding membranes of organically cross-linked gold nanoparticles (GNPs) interesting materials for applications in micro- and nanoelectromechanical systems. Here, we demonstrate the application of α,ω-alkanedithiol-cross-linked GNP membranes as electrostatically driven actuators. The devices were fabricated by depositing these membranes (thickness 29-45 nm) onto cylindrical cavities (diameter ∼200 μm; depth ∼8-15 μm), which were lithographically patterned in a SU-8 resist. Applying voltages of up to ±40 V across the membrane and the silicon substrate deflected the membranes by several hundreds of nanometers, as measured by atomic force microscopy, confocal microscopy, and interferometry. A simple electrostatic model, which takes into account the membranes' mechanical properties, was used to interpret the experimental data.
authors.affiliation: †Institute of Physical Chemistry, University of Hamburg, Grindelallee 117, 20146 Hamburg, Germany.
authors.forename: Hendrik
authors.initials: H
authors.lastname: Schlicke
authors.affiliation: †Institute of Physical Chemistry, University of Hamburg, Grindelallee 117, 20146 Hamburg, Germany.
authors.forename: Daniela
authors.initials: D
authors.lastname: Battista
authors.affiliation: †Institute of Physical Chemistry, University of Hamburg, Grindelallee 117, 20146 Hamburg, Germany.
authors.forename: Svenja
authors.initials: S
authors.lastname: Kunze
authors.affiliation: †Institute of Physical Chemistry, University of Hamburg, Grindelallee 117, 20146 Hamburg, Germany.
authors.forename: Clemens J
authors.initials: CJ
authors.lastname: Schröter
authors.affiliation: §Institute of Optical and Electronic Materials, Hamburg University of Technology, Eissendorfer Strasse 38, 21073 Hamburg, Germany.
authors.forename: Manfred
authors.initials: M
authors.lastname: Eich
authors.affiliation: †Institute of Physical Chemistry, University of Hamburg, Grindelallee 117, 20146 Hamburg, Germany.
authors.forename: Tobias
authors.initials: T
authors.lastname: Vossmeyer
keywords: MEMS; NEMS; actuator; electrostatic; freestanding; gold; membrane; nanoparticle