Silk Fibroin/Amino Acid Hybrid Organic Piezoelectric-Triboelectric Nanogenerator

AbstractTriboelectric nanogenerators (TENG) with great performance and biodegradability are desired for the expansion of novel medical devices and wearable electronics. The present study aims at the preparation of natural silk in the form of silk fibroin (SF) film for utilization in TENG and further improving its output efficiency by embedding organic-piezoelectric gamma-glycine (γ-gly) amino acid to be a hybrid-organic piezoelectric/triboelectric nanogenerator (HO-P/TENG). The attenuated total reflectance infrared spectroscopy (ATR-IR) results demonstrated the N-H, C = O, and C-N bonding for SF and SF/γ-gly, confirming its dominant effect with a strong electron-donating tendency from those amino groups. The scanning electron microscope (SEM) and synchrotron radiation X-ray tomographic microscopy (SR-XTM) images show good dispersibility of incorporated γ-gly on the surface and also inside the SF matrix relating to its content to improve the electrical performance homogeneously. By fabricating the device in the vertical contact-separation mode, the present SF/γ-gly HO-P/TENG at 15 wt% provides the maximum output voltage (VOC) and current (ISC) of 81 V and 121 μA with a maximum output power (Pmax) of 205 μW at the external load resistance of 5 MΩ. This SF-based HO-P/TENG has the advantage of being cost-effective with simple fabrication, demonstrating great promise for practical uses.Keywords: Silk fibroinamino acidhybrid organic piezoelectric-triboelectric nanogenerator Disclosure StatementNo potential conflict of interest was reported by the author(s).Additional informationFundingThe work of Thitirat Charoonsuk was funded by the Office of the Permanent Secretary, Ministry of Higher Education, Science, Research, and Innovation (OPS MHESI), Thailand Science Research and Innovation (TSRI), and Srinakharinwirot University under the Grant number RGNS 64-211. The work of Naratip Vittayakorn was supported by KMITL under Grant No. KREF116501. The work of Jitrawan Noisak was supported by King Mongkut's Institute of Technology Ladkrabang (KMITL) under Grant No. KREF016412 and The work of T. Bongkarm was supported by Naresuan University (NU) and National Science, Research and Innovation Fund (NSRF) with Grant No. R2567B001.