A high performance lead-free flexible piezoelectric nanogenerator based on AlFeO3 nanorods interspersed in PDMS matrix for biomechanical energy scavenging to sustainably power electronics

Abstract

Since lead-based piezoelectric nanogenerators (PENGs) possess serious health risks, environmental problems, proper disposal issues, and biocompatibility concerns, this work presents the fabrication of a flexible piezoelectric nanogenerator utilizing lead-free orthorhombic AlFeO3 nanorods for biomechanical energy scavenging to sustainably power electronics. Hydrothermal technique is used to synthesize the AlFeO3 nanorods and the PENG was fabricated on Indium tin oxide (ITO) coated Polyethylene terephthalate (PET) flexible film with AlFeO3 nanorods interspersed in polydimethylsiloxane (PDMS). transmission electron microscopy proved that the AlFeO3 nanoparticles are of nanorods shape. Through x-ray Diffraction, it is validated that AlFeO3 nanorods have orthorhombic phase and crystalline structure. A high piezoelectric charge coefficient (d 33 ) of 400 pm V−1 is obtained from the piezoelectric force microscopy of AlFeO3 nanorods. With optimized concentration of AlFeO3 in the polymer matrix, an open circuit voltage (V OC) of 30.5 V, current density (J C) of 0.7888 μA cm−2 and an instantaneous power density of 240.6 mW m−2 are obtained under the application of a force of 1.25 kgf. To investigate the nanogenerator’s practical utility, the PENG is used for lighting multiple LEDs, charging of a capacitor and as a pedometer via biomechanical energy harvesting. Hence, it can be employed for developing various self-powered wearable electronics such as flexible skin, artificial cutaneous sensors, etc.