Ultrasensitive and wearable strain sensors based on natural rubber/graphene foam

Abstract Recently, flexible strain sensors have attracted much attention, but there is still a challenge to manufacture flexible strain sensors with superb sensitivity and a large workable strain range simultaneously. Herein, a simple, rapid, and low-cost stratagem can be produced to fabricate novel strain sensors based on reduced graphene oxide (GO) foam in large quantities scalable. The PU sponge was used as a template to adsorb GO, and graphene foams (GF) was synthesized by pyrolyzing PU @ GO by the alcohol flame. Then the NR/GF composite was prepared by casting Natural Rubber (NR) latex into GF. The results showed that the gauge factor of the flexible sensor based on NR/GF composite reached 210 in the strain range of 10–40%. It could be used to detect motion, such as exercise steps, finger bending and identification strain types. Therefore, the NR/GF composites sensor has broad prospects of development in intelligent human-computer interaction, medical and other fields.