Advanced Piezoresistance of Extended Metal-Insulator Core-Shell Nanoparticle Assemblies

Abstract

Assembled metal-insulator nanoparticles with a core-shell geometry provide access to materials containing a large number (>10(6)) of tunneling barriers. We demonstrate the production of ceramic coated metal nanoparticles exhibiting an exceptional pressure-sensitive conductivity. We further show that graphene bi- and trilayers on 20 nm copper nanoparticles are insulating in such a core-shell geometry and show a similar pressure-dependent conductivity. This demonstrates that core-shell metal-insulator assemblies offer a route to alternative sensing materials.

Selective Chemical Modification of Graphene Surfaces: Distinction Between Single‐ and Bilayer Graphene

“…Recently we have used a wet-chemical method [7,10] to demonstrate the above concepts of chemically modifying graphene by covalently attaching organic moieties in a patterncontrolled way (lithography) onto a graphene model surface (highly oriented pyrolytic graphite (HOPG)). [11] More specifically, attachment of p-substituted benzene rings perpendicular to the graphene plain allowed to influence directly the surface potential by correctly choosing the benzene substituents.…”

Sintering of core–shell Ag/glass nanoparticles: metal percolation at the glass transition temperature yields metal/glass/ceramic composites

“…7 The conductivity across the gaps was explained by an electron hopping 16 or an electron tunnelling process. 17,18 Due to the many parameters influencing the percolation concentration, to which the filler distribution, filler shape, filler-matrix interactions and of course the synthesis method could be attributed as the most important ones, 12 the resulting system cannot easily be described by a theoretical model. Currently, most ceramic/metal composites (cermets) are obtained by hot-pressing, 11 sintering 4 or sputtering.…”

Chemical Aerosol Engineering as a Novel Tool for Material Science: From Oxides to Salt and Metal Nanoparticles

“…The temperature dependence, given by the negative temperature coefficient was similar or even enhanced when compared to commercial piezoelectric materials (Athanassiou et al 2006). The tunneling based conduction mechanism (Figure 4) showed that core/shell conductive/insulator materials offered a new and simple production route of highly sensitive pressure and temperature sensors (Athanassiou et al 2008;Athanassiou et al 2007b). Luechinger et al (2007) implemented carbon/copper nanoparticles in water based dispersions.…”