Recent progress on the fabrication and applications of flexible ferroelectric devices
Ferroelectric (FE) thin films that exhibit high piezoelectric coefficients and large FE polarization have been extensively investigated. The successful fabrication of flexible FE thin films was a milestone achievement in the research of ferroelectric thin films, which have prodigious potential and extensive foreground application in flexible wearable electronic devices, and since then, a large number of sensors, memory and energy harvesting devices have been fabricated. Here, we review the progress in recent years of the fabrication and applications of flexible FE devices. The fabrication methods of flexible FE thin films such as the formation of nanocomposites, etching of a sacrificial layer, laser lift-off and direct growth are summarized in this paper. Flexible wearable and implantable biomedical sensors, which designed for monitoring cellular deformations, gastrointestinal motility, blood pressure and soft tissue biomechanics, are also presented in this paper. We later discuss the different structures of energy harvesters and their working principles.