Flexible MoS₂ /silk fibroin composite piezoelectric nanogenerators for wearable self-powered sensing applications

Flexible MoS₂/silk fibroin composite nanofibrous membranes were fabricated via composite electrospinning for piezoelectric nanogenerators and wearable self-powered sensing. • MoS₂ nanoflowers acted as efficient nucleating agents to significantly promote the formation of β-sheet structures in silk fibroin, increasing its content from 40.96% to 47.22%. • The optimized composite membrane with 5 wt% MoS₂ loading delivers an open-circuit voltage of 5.41 V, approximately twice that of pristine silk fibroin membrane. • The composite membrane exhibits a high piezoelectric coefficient d₃₃ of 53 pC/N and maintains stable electrical output after 3300 cyclic compression tests. Bio-based silk fibroin (SF) typically exhibits suboptimal piezoelectric performance due to the low proportion of β-sheet crystalline domains and poor interfacial compatibility with inorganic fillers, which limits its application in flexible self-powered sensing. In this study, hydrothermally synthesized MoS₂ nanoflowers were doped into SF, and SF/MoS₂ composite nanofibrous membranes were fabricated via composite electrospinning, with their preparation process and piezoelectric properties systematically investigated. Acting as nucleating agents, MoS₂ nanoflowers significantly promote the formation of β-sheet structures in SF, increasing the content from 40.96% in pristine SF membranes to 47.22%. Synergizing with their intrinsic piezoelectric effect and optimized interfacial stress transfer, the composite membrane achieves an open-circuit voltage of 5.41 V, approximately twice that of pristine SF, and maintains stable output after 3300 cyclic compressions. Assembled into PENG devices, it was applied to human motion monitoring, enabling real-time detection of muscle contraction activities with clear signals, rapid response, and excellent repeatability, thus providing a novel strategy for self-powered sensing and wearable energy harvesting. Download: Download high-res image (139KB) Download: Download full-size image