Amorphous carbon interlayers for gold on elastomer stretchable conductors

M U Manzoor (1) , C L Tuinea-Bobe (1) , F Mckavanagh (1) , C P Byrne (1) , D Dixon (1) , P Maguire (1) , P Lemoine (1)

1 NIBEC

Gold on polydimethylsiloxane (PDMS) stretchable conductors were prepared using a novel approach by interlacing an hydrogenated amorphous carbon (a-C:H) layer between the deposited metal layer and the elastomer. AFM analysis of the a-C:H film surface before gold deposition shows nanoscale buckling, the corresponding increase in specific surface area corresponds to a strain compensation for the first 4-6 % of bi-axial tensile loading. Without this interlayer, the deposited gold films show much smaller and uni-directional ripples as well as more cracks and delaminations. With a-C:H interlayer, the initial electrical resistivity of the metal film decreases markedly (280-fold decrease to 8x10 -6 Ω.cm). This is not due to conduction within the carbon interlayer ; both a-C:H/PDMS and PDMS substrates are electrically insulating. Upon cyclic tensile loading, both films become more resistive, but return to their initial state after 20 tensile cycles up to 60% strain. Profiling experiments using Secondary ion mass spectroscopy (SIMS) and X-ray photoelectron spectroscopy (XPS) indicate that the a-C:H layer intermixes with the PDMS, resulting in a graded layer of decreasing stiffness. We believe that both this graded layer and the surface buckling contribute to the observed improvement in the electrical performance of these stretchable conductors.

Mots clés: Physical Sciences

M U Manzoor, C L Tuinea-Bobe, F Mckavanagh, C P Byrne, D Dixon, et al.. Amorphous carbon interlayers for gold on elastomer stretchable conductors. Journal of Physics D: Applied Physics, 2011, 44 (24), pp.245301. ⟨10.1088/0022-3727/44/24/245301⟩. ⟨hal-00625565⟩