Electric field-assisted construction of bionic directional channels enhances charge storage in MXene/Ecoflex triboelectric nanogenerators for self-powered sensing

Triboelectric flexible wearable sensors provide a new momentum for the intelligent and digital development of rehabilitation medicine, and effectively address the key challenges of sensor power supply, sensitivity, and comfort. However, the lack of reliable control methods for material doping makes it difficult to further enhance the sensitivity of triboelectric sensors. Inspired by the efficient water transport mechanism in plants, this study employed an AC electric field-assisted method to fabricate MXene/Ecoflex composite films (ACC films) with an oriented structure. The influence of the electric field on MXene orientation behavior and its formation mechanism were systematically investigated. Experimental results demonstrate that the oriented MXene filler effectively enhances the film's charge storage capacity and reduces charge dissipation, thus significantly improving the output performance of the triboelectric nanogenerator (TENG). The open-circuit voltage, short-circuit current, and charge density of ACC-TENG prepared under a 600 V/mm electric field increased by 25.2 %, 34 %, and 31 %, respectively, comparing to the film without an applied electric field. Ultimately, the constructed ACC-TENG was applied as a flexible sensor for human motion monitoring and rehabilitation assessment, achieving highly sensitive detection of subtle motion features such as joint flexion duration, flexion angle, and finger tremors during gripping (with conventional gripping signals reaching 20 V output). This provides innovative material design concepts and technical pathways for the advancement of intelligent rehabilitation medicine.