An editable yarn-based flexible supercapacitor and integrated self-powered sensor

The rapid development of supercapacitors and wearable devices has allowed the construction of integrated self-powered wearable devices. However, most current research focuses on increasing supercapacitor capacity and the sensitivity of sensors, overlooking the self-powered and integration of one single device. In this study, the editable, flexible yarn-based supercapacitor (FYSC) and an integrated self-powered wearable sensor (SPWS) were constructed based on one yarn. The FYSC demonstrated adjustable capacitive behaviors by controlling the electrode reduction degree, electrode spaces, and integration. The supercapacitors exhibit a high specific capacitance of 1.82 F cm⁻³, 92.57% capacity retention after 5000 cycles, and stable performance under static and dynamic strain conditions. Additionally, the integrated SPWSs demonstrated the accuracy and sensitivity in discriminating bending magnitudes. The SPWSs further present the accuracy and stability in recognizing human physiological activities (joint motions of finger, wrist, knee, and elbow, respiration, and handwriting). The proposed strategy offers a practical approach to developing energy storage systems with customizable functionality. More importantly, the self-powered devices realized the integration of supercapacitors and sensors would facilitate the seamless integration of 1D functional yarns into wearable electronics.