0D to 2D carbon-based materials in flexible strain sensors: recent advances and perspectives

In the past decade, flexible strain sensors have attracted much attention in the fields of health care, soft robots and other flexible electronics due to their unique flexibility, high stability, and strong mechanical properties. To further meet the requirements of the excellent performance for electronic equipment, carbon-based conductive sensitive materials have become one of the first choice for the preparation of flexible strain sensors due to their excellent electrical conductivity, mechanical properties, and high compatibility. Herein, based on different strain behaviors, this paper analyzes the working mechanism of tensile and compressive strain sensors, focusing on the latest research progress of carbon-based conductive materials in strain sensors with different dimensions. The applications of carbon-based sensitive materials with multifunctional strain sensing in the areas of physiological information detection, human motion, human-machine interaction, and visual display have also been summarized. Furthermore, it has been attempted to discuss the current challenges of carbon-based strain sensors as well as the prospect of flexible strain sensors. This review is aimed to provide appropriate references for further exploitation of multi-functional flexible carbon-based strain sensors.