Enhancing Piezoelectricity of Silk Fibroin Through In Situ Growth of Metal‐Free Perovskite for Organic and Eco‐friendly Wearable Bioelectronics

Abstract The biosafety and sustainability of inorganic perovskites or organic piezopolymers is a major concern in the field of wearable piezoelectric sensors. Naturally occurring, silk fibroin (SF), is a promising alternative for the realization of organic piezoelectric devices due to its excellent biocompatibility and tunable material properties. Nevertheless, its scope for practical sensing applications is limited by the weak innate piezoelectricity of 1 pC N −1 . This research aims to improve the piezoelectricity of pristine SF by intrinsically growing non‐toxic metal‐free perovskite (MFP) to achieve organic and bendable silk fibroin‐metal free perovskite (SF‐MFP) composite films. The increase in MFP loading has an influence on the resulting morphology and crystallinity of SF‐MFP films. In comparison to pristine SF, the films with the highest perovskite loading exhibit an enhanced normal piezoelectric response of 4.6 pm V −1 . The poled SF‐MFP sensors display an appreciable sensitivity of 0.61 ± 0.05 V N −1 with a fast response time and outstanding stability arising from a synergistic combination of mechanically robust SF and piezoelectric MFP. Furthermore, these sensors can detect various joint bending and muscle movements in human subjects, proving their suitability for wearable bioelectronics. This research demonstrates the potential of biomaterials and organic perovskites for the development of biocompatible and sustainable wearable piezoelectric solutions.