Environmentally-friendly conductive cotton fabric as flexible strain sensor based on hot press reduced graphene oxide

A flexible conductive cotton fabric was demonstrated by formulation and deposition of a graphene oxide (GO) dispersion onto a cotton fabric by vacuum filtration. The deposited GO amount was controlled by the concentration and volume of the GO dispersion. The GO was reduced by a hot press method at 180 degrees C for 60 min, and no chemical reductant was needed in both the deposition and reduction processes. The carbon-oxygen ratio increased from 1.77 to 3.72 after the hot press reduction. The as-prepared flexible conductive cotton fabric showed a sheet resistance as low as 0.9 k Omega/sq. The sheet resistance of the conductive cotton fabric only increased from similar to 0.9 k Omega/sq to similar to 1.2 k Omega/sq after 10 washing cycles, exhibiting good washability. The conductive cotton fabric showed viability as a strain sensor even after 400 bending cycles, in which the stable change in the electrical resistance went from similar to 3500 k Omega under tensile strain to similar to 10 k Omega under compressive strain. This cost-effective and environmentally-friendly method can be easily extended to scalable production of reduced GO based flexible conductive cotton fabrics. (C) 2016 Elsevier Ltd. All rights reserved.