Composite silicone rubber of high piezoresistance repeatability filled with nanoparticles

The ruthenium oxide nanoparticles with size less than 20 nm were fabricated by annealing the metallic ruthenium nanoparticles in air, which were synthesized by using the thermal reduction in the polyol solution. The rutile structure of the ruthenium oxide was proved by using transmission electron microscopy (TEM) and X-ray photoelectron spectroscopy (XPS). The oxide has good electron conductivity. The surface of the ruthenium oxide was modified by a vinyl silane coupling agent. The assembling of the silane to the oxide surface was proved by Infrared (IR) absorption spectroscopy. By mixing the nanoparticles with poly(methylvinylsiloxane) (PMVS) silicone rubber, a composite filled with dispersive conducting phase was fabricated. The temperature dependent conductivity shows that the electron transportation through composite is mainly dominated by tunneling. The measurement of piezoresistance shows that the composite at low strain has high piezoresistance repeatability. The 3D reconstruction images of the composite filled with carbon black or ruthenium oxide show that the aggregation of the nanoparticles differs much for two composites. The narrow distribution range of the particle size was thought to be the main factor for the high piezoresistance recurrence.