Polyurethane sponges decorated with reduced graphene oxide and silver nanowires for highly stretchable gas sensors

Unlike the stretchable physical sensors such as stretchable pressure sensors, strain sensors, and temperature sensors, few works have been reported on the stretchable gas sensors. This study presents that stretchable gas sensors can be fabricated by decorating reduced graphene oxide/silver nanowires (rGO/AgNWs) hybrids on the porous polyurethane (PU) sponges using a facile dip-coating method. The sensors show good room-temperature responses to NO₂ gas under both a bending strain (r = 3 mm) and a large tensile strain up to 60%. The response of about −15% is measured at a 50 ppm of NO₂ under a 60% strain. Furthermore, reducing gases like acetone and ethanol can also be detected under the large strains. The results of this study offer a new insight into realization of highly stretchable and easy-to-fabricate gas sensors.