Stretchable and magneto-sensitive strain sensor based on silver nanowire-polyurethane sponge enhanced magnetorheological elastomer

摘要

This work reported a stretchable, compressible and magneto-sensitive strain sensor based on conductive magnetorheological elastomer (MRE) containing silver nanowires (AgNWs) dip-coated polyurethane sponge, carbonyl iron particles and polydimethylsiloxane (PDMS) matrix. The mechanic-electric-magnetic coupling properties of conductive MRE were investigated and they were significantly influenced by mechanical properties of PDMS matrix and the AgNWs content. By increasing curing agent weight ratio, the cross-linking density of the PDMS increased thus the magneto-induced modulus decreased. The MRE was able to be used in the strain sensors, because its relative resistance variation reached 91.8% and 67.6% when 20% tensile strain and 10% compressive strain were applied. By applying a 428 mT magnetic field, the relative resistance of MRE sensor increased to 200%. Based on the experimental results, a possible mechanism was proposed to investigate the mechanicelectric-magnetic coupling sensing characteristics. Finally, the MRE sensors can be integrated on a shoe to detect the foot motion, demonstrated this material was promising in the intelligent devices like artificial skin, composite electrodes and soft sensor. (C) 2018 Published by Elsevier Ltd.