Sheath-Core Fiber Strain Sensors Driven by in-Situ Crack and Elastic Effects in Graphite Nanoplate Composites

Flexible and stretchable electronics, e.g., graphite-nanoplatelet-based (GNP-based) nanocomposite devices, have attracted great interest due to their potential application in health care, robotics, and mechatronics technology. However, the deficient sensors with manipulation of low sensitivity, sluggish responsivity, sophisticated fabrication process, and poor repeatability notoriously limit their industrial applications. For an enhancement in the spontaneous sensitivity, flexibility, and wearability in GNP-based strain sensors, in this report, synergistic crack and elastic effect engineering is employed and in turn significantly enhances the sensitivity with a gauge factor of 20 at a strain of 30% and the stability in our developed sheath-core fiber (SCF) strain sensors. Upon reliable device integration, it is demonstrated that the developed SCF strain sensor could detect the movement of a human joint effectively with generating a resistance change rate Delta R/R-0 up to 600%. Furthermore, a controlling device system based on the SCF strain sensor has been manufactured at the circuit level to realize the real-time control of a robot hand, such as copying gestures and playing piano.