Electrospinning ultrafine graphene nanofibers for flexible sensors

The rapid advancement of wearable healthcare monitoring and athletic performance tracking devices has intensified the demand for high-conductivity flexible sensors with high sensing performance. Despite their excellent electrical conductivity, graphene fibers exhibit limited flexibility, constraining their applications in flexible sensors. Here, we produced ultrafine graphene nanofibers via electrospinning of nano-sized graphene oxide sheets, significantly improving the flexibility of graphene fibers and the corresponding non-woven fabrics. With a diameter of 66 nm, which is two orders of magnitude thinner than common graphene fibers, the non-woven fabrics made of randomly distributed graphene nanofibers exhibited exceptional flexibility, affording sensors with bending flexibility, a wide strain range, a low detection limit and good cycling stability. By capturing resistance signals from sensors located at the throat, finger joints, knees, and other sites, we achieved effective word recognition and human motion monitoring. This work establishes a method for fabricating ultrafine fibers from two-dimensional materials, greatly advancing the development of wearable devices.