Selaginella iepidophylla-Inspired cellulose nanofibers/graphene oxide biomimetic asymmetric film for multimodal simultaneous self-powered monitoring(BAMS) of respiration and sweat

Real-time and simultaneous monitoring of respiration and sweat status is of great significance for assessing human motion states. Inspired by Selaginella lepidophylla , this study designed a self-powered multimodal sensor based on a biomimetic asymmetric CNF/GO film. At the material level, an asymmetric film was fabricated using gradient drying and unilateral imprinting, achieving a maximum bending angle of 55° under humidity stimulation. At the device level, the TENG sensor integrated with PTFE achieved a maximum output voltage of 2.564 V. It exhibited distinct temporal characteristics and anti-interference capability in response to airflow and water vapor, while maintaining stable performance after 500 cyclic loadings. At the application level, the sensor effectively distinguished different breathing patterns and sweat variations across different body regions, and enabled physiological signal monitoring under resting, aerobic, and anaerobic conditions. Using professional athletes as subjects, wearable experiments were conducted for four types of sports: 400 m running, tennis, volleyball, and basketball. The sensor accurately captured changes in respiration and sweat signals before and after exercise. The observed signal differences corresponded well with the energy expenditure ratings of smartwatches, effectively distinguishing physiological response variations under different exercise intensities.