  Assembled metal/insulator nanoparticles with a core/shell geometry provide
access to materials containing a large number (>106) 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 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.
