Moisture-Enabled Electric Generators Based on Electrospinning Silk Fibroin/Poly(ethylene oxide) Film Impregnated with Gradient-Structured Sericin

Moisture-enabled electric generations (MEGs) are highly promising in next-generation energy conversion, while those derived from sustainable biomass are still in their infancy. Protein nanostructures possess intriguing abilities to harness ion transportation for bioelectricity generation. Herein, quality-enhancing MEGs with silk cocoon-like structure were developed. In this context, silk fibroin nanofiber film was first electrospun, and a sericin concentration gradient along the thickness direction was created through a simple spraying technique. Owing to the good moisture absorption capacity, abundant dissociated ions, and numerous micro-nanoscale channels, the maximum open-circuit voltage and short-circuit current of the prepared MEGs were 276 mV and 70 nA, respectively, at 95% relative humidity. In addition, MEG can deliver voltage for nearly 2.5 h without degradation. Because of cell membrane blebbing induced by sericin, the bacteriostatic rate of the MEGs against both S. aureus and E. coli was more than 80%. Particularly, the MEGs demonstrated successful applications in self-powered sensors, including a human respiratory rate and different states of human movement. Our study offers insight into the future development of flexible, efficient, and easily fabricated protein-based MEGs.