All-inkjet-printed flexible piezoelectric generator made of solvent evaporation assisted BaTiO₃ hybrid material

Attractive approaches based on flexible piezoelectric energy harvesting technology that convert ambient mechanical energies into electrical energy have attracted attention in response to recent progress in the field of flexible electronics technology. Although the harvesters on plastic substrates has shown the feasibility of the piezoelectric energy generation from the repetitive and tiny bending deformations, the complicated fabrication process and size limitations hinder the commercialization of piezoelectric self-powered technology. In this study, all-inkjet-printed flexible piezoelectric energy harvester based on a BaTiO₃ hybrid film is demonstrated by adopting only a simple and facile inkjet-printing process. Flexible/large-area piezoelectric hybrid film and Ag electrode layers are printed onto a flexible substrate by only non-contact inkjet process without high temperature annealing and complicated transfer processes. All-inkjet-printed energy harvester converts the periodically mechanical deformations into an open-circuit voltage (V_oc) of ~ 7 V, a short-circuit current (I_sc) of 2.5 μA (corresponding to a current density of 0.21 μA·cm⁻²), and an effective output power of around 5 μW (corresponding to a power density of 0.42 μW·cm⁻²). This novel approach provides an innovative platform for self-powered system and inorganic-based flexible electronics.