Biomass-derived multifunctional 3D film framed by carbonized loofah toward flexible strain sensors and triboelectric nanogenerators

The ever-increasing complexity of social activities has yielded the call for wearable electronics with combined high performance and multifunction. Although the introduction of three-dimensional (3D) structures has proved to be a promising approach, the complicated fabrication process, hazardous precursors, and undesirable performance of 3D structures may pose challenges for developing advanced electronics. Herein, a green and cost-effective carbonized loofah (CL) was fabricated into a versatile flexible electronic for both strain sensing and energy harvesting. The maintained 3D architectures of CL have a promotive effect on improving the responding sensitivity. Therefore, the CL-based strain sensor exhibits advanced characteristics, such as ultrahigh sensitivity (GFmax = 14,639.06), short response time (30 ms), ultralow detection limit (0.01% strain), and good durability (2000 cycles). These features endow the CL with efficient discernibility to monitor multiple complicated human activities (e.g., pulse rate, breathing, phonation). Furthermore, the CL can act as a flexible triboelectric nanogenerator (TENG) for energy collection, providing a potential sustainable energy supply for the continuous working of the sensing system. Therefore, the biomass-derived CL with instinct structures may be a promising platform for the fabrication of multifunctional wearable devices for human health monitoring and portable power sources.