▎ 摘 要
It remains a challenge to achieve high sensitivity and a broad linear strain range simultaneously for wearable strain sensors. Specially, graphene-based strain sensors always exhibit low sensitivity owing to the slippage of graphene flakes. To overcome this problem, Al3+ is used here as "mortars" for graphene flakes instead of polymers usually used in the literature, and thus a very simple and low-cost strategy is developed to prepare a high-performance reduced graphene oxide coated fiber strain sensor. The strain sensor shows a low detection limit (0.1% strain), high sensitivity, and a very broad linear sensing range (0-20%, R-2 = 0.99, GF = 322), which is attributed to the occurrence of uniform microcracks under stretching induced by Al3+ as well as the large variation of the overlapped area between adjacent graphene flakes at small strain (<1% strain). Moreover, the good cycle stability and durability against water washing of the strain sensor are verified. The excellent properties of the wearable strain sensor ensure it successfully applied in the real-time monitoring of human activities.