|Title||Strain sensitivity in ion-implanted polymers|
|Publication Type||Presentazione a Congresso|
|Year of Publication||2009|
|Authors||Di Girolamo, G., Massaro M., Piscopiello E., Pesce Emanuela, Esposito C., Tapfer L., and Antisari M.V.|
|Conference Name||Materials Research Society Symposium Proceedings|
|Conference Location||Boston, MA|
|Keywords||Compression testing, Compression tests, Conducting films, Conductive films, Copper, Copper films, Cu nanoparticles, Electric conductivity, Electrical conductivity measurements, Electrical property, Electrical resistances, Fluences, Gages, Inert polymers, Ion bombardment, Ion implantation, Light absorption, Linear variation, Low energies, Nanocrystalline Cu, Nanocrystals, Nanoparticles, Optical absorption spectrum, Polycarbonate substrates, Polymer surfaces, Radiation induced damage, Room temperature, Size distribution, spatial distribution, Strain gauge, Strain sensitivity, Surface loads, surface plasmon resonance, Surface resistance, Surfaces, TEM, TRIM calculations, Ultra-thin, XRD|
Ion implantation process was used to fabricate ultra-thin conducting films in inert polymers and to tailor the surface electrical properties for strain gauge applications. To this aim, polycarbonate substrates were irradiated at room temperature with low energy Cu+ ions of 60 keV at 1 μA/cm2 and with doses ranging from 1×1016 to 1×1017 ions/cm2. XRD and TEM measurements on the nanocomposite surfaces demonstrated the spontaneous precipitation of Cu nanocrystals at 1×1016 ions/cm2 fluence. These nanocrystals were located at about 50 nm - 80 nm below the polymer surface in accordance with TRIM calculations. Optical absorption spectra exhibited a surface plasmon resonance (SPR) at 2 cV, in accordance with the formation of Cu nanoparticles. For doses of 5×1016 ions/cm2 the formation of a continuous nanocrystalline Cu subsurface film occurred and a well pronounced SPR peak was observed. Otherwise, for higher doses (1×10 17 ions/cm2) a damaged and structurally disordered film was obtained and the SPR peak was smeared out. Electrical conductivity measurements clearly indicated a reduced electrical resistance for the samples implanted with a doses up to 5×1016 ions/cm2 , whereas higher doses (1×1017 ions/cm2) resulted detrimental for the electrical properties, probably due to the radiation induced damage. The dependence of electrical resistance from surface load was evaluated during compression tests up to 3 MPa. A significant linear variation of the electrical resistance with the surface load was found and could be related to the changes in the spatial distribution of nanoparticles inside the copper film. © 2009 Materials Research Society.