Scaling effect of flexoelectric (Ba,Sr)TiO₃ microcantilevers

The flexoelectric microcantilever offers an alternative approach for the development of micro/nano-sensors. The transverse flexoelectric coefficients μ₁₂ of barium strontium titanate microcantilevers were measured at room temperature, and found to keep the same value of 8.5 μC/m for microcantilevers with thickness ranging from 30 μm to 1.4 mm. The calculated effective piezoelectric coefficient and electrical energy density of flexoelectric cantilevers are superior to those of their piezoelectric counterparts, suggesting that the flexoelectricity-induced polarization can be significantly increased as structures are scaled down due to the scaling effect of strain gradient, holding promise for flexoelectric micro/nano cantilever sensing applications.