Specific diets are green and efficient method to obtained enhanced robustness silkworm silk, which has been attracted particular research interest. Graphene oxide is widely used for biomedicine and reinforcement. Thus, in this work, we reported enhanced mechanically silk directly collected by feeding Bombyx mori silkworms with graphene oxide and its physiology of silkworm was explored. These results suggested that feeding graphene oxide can promote silkworm growth and development slightly. And cocoon weight was also increased by feeding graphene oxide. Furthermore, it was found that the activity of alkaline phosphatase related to absorption and metabolism, the content of reduced glutathione related to antioxidant capacity were increased with graphene oxide incorporation. The stability of silk protein in silk glands was also changed with graphene oxide incorporation. And the content of amino acids in the hemolymph and silk were affected. In addition, it suggested that feeding graphene oxide has a great influence on the secondary structure of silk, resulting in the reduction of β-sheet structure, crystallinity, crystal size, and the increase of orientation, polar amino acid content, intermolecular force. Thus, mechanically processed silk was obtained, demonstrating significant potential for utilization in the fields of reinforced composites and biomedicine.

Flexible sensors is becoming the focus of research due to its very vital for intelligent products, real-time data monitoring and recording. The flat silk cocoon (FSC), as a special form of cocoon, has all the advantages of silk, which is an excellent biomass carbon-based material and a good choice for preparing flexible sensors. In this work, a flexible piezoresistive sensor was successfully prepared by encapsulating the carbonized flat silk cocoons (CFSC) using an elastic matrix polydimethylsiloxane (PDMS). The sensing performance of the material is -0.01 kPa-1. And the monitoring range can reach 680.57 kPa. It is proved that the sensor can detect human motion and has excellent durability (>2000 cycles). In addition, the sensor array for keyboard based on CFSC was explored. The sensor has low production cost, simple preparation process, sustainable and environmentally friendly, which might be expected to have potential applications in wearable devices and human computer interaction.