Controllable Piezo-flexoelectric Effect in Ferroelectric Ba_0.7Sr_0.3TiO₃ Materials for Harvesting Vibration Energy

The rapid development of the automotive and aerospace industries has led to an increasingly urgent need for electromechanical coupling materials and devices. Here, we have demonstrated the tunable piezo-flexoelectric effect in ferroelectric Ba_0.7Sr_0.3TiO₃ materials for scavenging vibration energy. The positive peak output current of an ITO/Ba_0.7Sr_0.3TiO₃/Ag cantilever device based on the flexoelectric effect is only 45 nA at room temperature, which is promoted to 90 nA by the piezo-flexoelectric effect. In addition, the piezo-flexoelectric current of the device can be further boosted to 270 nA by increasing the working temperature to 41.0 °C with a corresponding enhancement ratio of 348.28%. The significantly improved piezo-flexoelectric current is ascribed to the ultrahigh dielectric constant, which is related to the tetragonal-cubic phase transition of the Ba_0.7Sr_0.3TiO₃ materials. This work reveals the temperature-modulated piezo-flexoelectric effect in ferroelectric Ba_0.7Sr_0.3TiO₃ materials, providing a convenient route for scavenging and sensing of vibration energy.