Fibrous self-powered sensor with high stretchability for physiological information monitoring

Triboelectric nanogenerator (TENG) can convert mechanical energy into electricity, thus realizing the development of a new type of self-powered wearable sensors, which generate electric signals directly upon mechanical stimuli. On another hand, good stretchability is also an essential character of the wearable sensors to guarantee deformation consistence with the human body. In this work, a fibrous stretchable TENG-based sensor (FS-TENG sensor) with core-sheath structure is fabricated and applied in physiological monitoring. The output open-circuit voltage and shout-circuit current of FS-TENG sensor can reach nearly 10 V and 0.6 μA, respectively. The elastic substrates and stretchable electrodes provide the FS-TENG sensor with good resilience, and the output voltage of the sensor keeps stable under 60% strain extension, demonstrating the stability of the sensor at large deformation. Meanwhile, the FS-TENG sensor can detect ultralow pressure down to 0.02 N and achieve 26.75 V N−1 in low pressure, showing its ultralow detection limit and outstanding sensitivity to external force. Taking advantage of the excellent sensing performance of the FS-TENG sensor, we applied it in the human motions monitoring, including large movements (joints bending and step) and subtle vital signs (pulse, phonation, and expression). Moreover, a tactile sensor array with 3 × 3 pixels is fabricated by weaving 6 FS-TENG sensors to realize the pressure distribution recognition.