Silk fibroin-based biodegradable piezoelectric composite nanogenerators using lead-free ferroelectric nanoparticles

Silk fibroin-based biodegradable composite-type nanogenerators are demonstrated with controllable lifetime for powering to the implantable devices. The composites consist of the well-dispersed lead-free ferroelectric (BaTiO3, ZnSnO3, Bi0.5(Na0.82K0.18)0.5TiO3, and K0.5Na0.5Nb0.995Mn0.005O3) nanoparticles. A maximum output voltages and current densities of 2.2 V and 0.12 µA/cm2 in the thin film, and 1.8 V and 0.1 µA/cm2 in the wire are obtained under the motion of a foot step.