Enhanced Performance of Graphene-Epoxy Flexible Capacitors by Means of Ceramic Fillers

Graphene-epoxy fl exible capacitors are obtained by graphene-polymer transfer and bonding via UV-cured epoxy adhesive. Ceramic fi llers are dispersed into the epoxy resin with the aim of enhancing the capacitive behavior of the fi nal device. Parallel plate capacitors in which epoxy resin is fi lled with ceramic nanoparticles demonstrate superior performance, up to two orders of magnitude better than unfilled samples. Zirconia, showing the highest dielectric constant, fails to give a stable output in the whole frequency range, as some competing phenomena occur and reduce the overall polarization of the system. Boehmite appears to be a better choice and gives reasonable performances, better than gibbsite.