Silk Fibroin-Based Triboelectric Nanogenerators for Energy Harvesting and Biomedical Applications

Triboelectric nanogenerators (TENGs) developed from eco-friendly natural materials rather than traditional electronic materials are more favorable for biocompatible applications and for use in sustainable life-cycle analysis. Silk fibroin (SF) has emerged as an abundant natural biomaterial that shows great potential in the preparation of TENGs. Silk-based triboelectric nanogenerators (SF-TENGs) have green energy harvesting properties, are environmentally friendly, are biocompatible, are not fully present in conventional TENGs, and are important for the next generation of self-powered electronic devices. In this review, the latest progress in SF-TENGs, including their applied materials, structural properties, manufacturing processes, and application scenarios, is discussed. These SF-TENGs show great potential for use in emerging energy and electronic applications as well as smart living and medical assistance. In addition, the potential value of SF-TENGs has been further explored, and the possibility and main challenges of expanding and applying SF-TENGs to the field of microneedles (MNs) are discussed.