Freestanding Nanocomposite Membranes as Highly Sensitive MEMS Pressure/Force Sensors

H. Schlicke, S. Kunze, M. Rebber, T. Vossmeyer
Fraunhofer Center for Applied Nanotechnology,

Keywords: gold nanoparticles, membranes, thin films, pressure sensors, charge transport


In this contribution we present highly sensitive pressure sensors markedly exceeding a resistive pressure sensitivity of ~1*10^-4 mbar^-1. We exploit the flexibility and resistive strain sensitivity of freestanding membranes of gold-nanoparticles, cross-linked using alkanedithiol molecules. While having thicknesses of only a few tens of nanometers, the membranes are employed both, as diaphragms and strain-sensitive transducers in gauge pressure sensors as well as differential pressure sensors. Besides their application in prototypical pressure sensors we present our latest investigations targeting the electromechanical characterization of freestanding GNP membranes. Using micro-bulge test experiments with atomic force microscopy (AFM) based deflection readout, we demonstrate that - along with their electronic and optical characteristics - the mechanical properties of GNP nanomembranes can be adjusted by the choice of the cross-linking dithiol molecules. Further, we present first results regarding the electromechanical characterization of freestanding GNP membranes employing combined AFM and charge-transport measurements.