A flexible and sensitive 3D carbonized biomass fiber for hybrid strain sensing and energy harvesting.

[Display omitted] • A flexible and highly sensitive strain sensor was developed by using carbonized biomass Juncus effusus fiber. • The 3D fractal composite structure showed robust mechanical strength and excellent sensitivity. • Reliable sensing performance was achieved with mechanism revealed. • Potential applications include health care monitoring and human motion monitoring were demonstrated. • The promising potential of energy conversion and harvesting was demonstrated. Fabricating strain sensors with environmental-friendly, stretchable, and highly sensitive properties remains challenging. Nature has designed an abundance of biomaterials with distinctive biological structures, which may promote the development of ideal strain sensors. Herein, we present a carbonized Juncus effusus (CJE) fiber-based wearable electronic for strain sensing and energy harvesting. The CJE strain sensor demonstrated a combined superiority of large tolerable strain (over 80%), high sensitivity (GF 4.5–31.0), low detection limit (0.1% strain), fast response (within 100 ms), and excellent durability (3500 cycles), which benefit from the self-similar and homogenous three-dimensional (3D) networks of CJE fibers. Moreover, CJE-based woven fabrics exhibited enhanced sensing characteristics (GF up to 101.9, over 110% strain) and great application prospects as triboelectric nanogenerators (TENGs). Finally, the applications in detecting human activities and energy transformation were evaluated in detail. The structural advantages made CJE as a promising candidate for the feasible integration of flexible strain sensors and portable power source in wearable electronics. [ABSTRACT FROM AUTHOR]