Self-powered wearable graphene fiber for information expression

With the fast development of wearable electronics, portable energy generation devices are attracting our considerable attention. Among them, the wearable self-powered system spontaneously harvesting energy from the environment will be much needed. Herein, a high-performance graphene fiber power generator (GF-Pg) is produced based on graphene oxide (GO) fiber. The GF-Pg has highly oriented GO sheets assembled within the fiber, which provide favorable channels for efficient ion transport and thus harvests energy from the moisture. A single fiber generator unit with a length of less than 1 mm and a diameter of 80 µm was able to supply a voltage output of 355 mV in response to the humidity variation, which could be enhanced to 1.3 V by simply increasing the number of device units. Impressively, this moisture-enabled self-powered fiber could be integrated into flexible textiles to realize an information storage/expression based on the breath activated electronic labels of GF-Pg, demonstrating the promising applications in wearable electronics.