Ultra-thin and sensitive pressure sensor based on MXene/PVDF-HFP composite fiber TENG for self-diagnosis of ligament injuries

Abstract

Early screening of anterior cruciate ligament (ACL) injuries using wearable devices enables timely intervention and reduces the risk of chronic complications. However, the subtle biomechanical signals of the ACL pose challenges to the baseline stability, sensitivity and skin adherence of wearable devices. Here, we present a TENG based on MXene/PVDF-HFP composite fibers for ACL self-diagnosis, leveraging the inherent advantages of TENG in baseline stability. The fiber-network structure prepared by electrospinning ensures that the TENG is ultra-thin and flexible to wear. The addition of MXene significantly increases the relative permittivity of the electrode materials, and re-modulates the crystalline phase (α and β). Consequently, the peak-to-peak open circuit voltage of the TENG reaches 160 V under a pressure of 10 N. It can respond to pressures as low as 0.01 N, allowing it to distinguish subtle relative displacements between the tibia and the knee. Integrated with a mobile app, a self-diagnostic system capable of detecting varying degrees of ACL injury has been developed. We expect this approach to facilitate the early detection and timely treatment of ACL injuries.