Synergism of binary carbon nanofibres and graphene nanoplates in improving sensitivity and stability of stretchable strain sensors

Stretchable strain sensors with high sensitivity and good stability are crucial for wearable healthcare devices and tactile sensors for robots. Herein we present a new technique to synergistically improve sensors' sensitivity and cyclic stability by hybridising carbon nanofibers (CNFs) with graphene nanoplates (GNPs) within polydimethylsiloxane (PDMS) medium. The results reveal that, compared with equivalent sensors containing only CNFs or GNPs, the hybridised sensors show significantly better performance with a greater linear range up to similar to 50% of strain and much-improved stability (less drift) under repeated loading, which is quantitatively reflected by the synergy ratio of linear range and drift rate. Increasing the concentration of hybrid carbon fillers can further increase sensors sensitivity. Therefore, the hybridisation of 1D and 2D nano-carbon materials offers a new route for increasing the sensitivity and cyclic stability of flexible strain sensors.