Electrical and electromechanical properties of stretchable multilayer-graphene/PDMS composite foils.

Multilayer graphene (MLG)/polydimethylsiloxane (PDMS) composite foils are developed for possible application in wearable electronics as stretchable conductors or in strain sensing. The MLG/PDMS foils are prepared through infiltration of PDMS into porous freestanding MLG papers. The freestanding MLG papers are first produced through vacuum filtration of MLG-flake suspensions and are characterized by sheet resistance in the range from ~0.7 to ~1.1 Ω/□ and average thickness in the range from ~75 to ~110 μm. The electromechanical characteristic of the produced MLG/PDMS foils is assessed experimentally by measuring the dc electrical resistance of the produced specimen during tensile strength tests. It results that the breaking load of the new composite foils, occurring after an elongation of ~11 mm, which corresponds to a deformation of ~80%, is nearly doubled with respect to the one of neat PDMS. Moreover, for an elongation up to 2 mm the total dc resistance of the foil exhibits an increase lower than the 20% of its original value.