Efficient natural piezoelectric nanogenerator: Electricity generation from fish swim bladder

Highlights: • The direct fabrication of an efficient bio-piezoelectric nanogenerator (BPNG) from fish (Catla Catla) swim bladder (FSB). • The self-alignment of the molecular dipoles in the FSB collagen is confirmed by the angular dependent Near edge X-ray Absorption Spectroscopy (NEXAFS). • The large piezoelectric charge coefficient (d₃₃~22 pC/N) enables the BPNG to generate the open-circuit voltage of 10 V and short-circuit current of 51 nA under compressive normal stress (~1.4 MPa) by human finger. • The high power throughput of 4.15 μW/cm² with inherent piezoelectric energy conversion efficiency (~0.3%). • Furthermore, the BPNG instantly turns on more than 50 commercial blue LEDs which are unable to drive by a battery of 8.66 V. For real time demonstration we have also provided the associated video files mentioned in the supporting file. An efficient bio-piezoelectric nanogenerator (BPNG) is fabricated from the fish swim bladder (FSB), composed of well-aligned natural collagen nano–fibrils. The self-alignment of highly ordered structure in the FSB collagen has been confirmed by angular dependent near edge X-ray absorption fine structure (NEXAFS) spectroscopy. Compressive normal stress by human finger can able to drive the BPNG that generates an open-circuit voltage of 10 V and short-circuit current of 51 nA. The generated electricity from the FSB instantly turns on more than 50 commercial blue light emitting diodes (LEDs), indicates to use as a sustainable power source in portable electronic devices where the bulky battery counterpart can be avoided. The instantaneous piezoelectric power generation (~4.15 μW/cm²) and substantial energy conversion efficiency (~0.3%) of BPNG promises an emerging application, particularly to built self-powered biomedical sensors because collagen itself one of the most abundant protein available in human body.