fig9

Figure 9. Flexoelectronics enabled by strain gradient-induced polarization. (A and B) (A) Schematic and (B) finite-element simulation of an AFM-tip-induced strain gradient in ultrathin SrTiO₃ films; (C) Band-structure evolution under increasing flexoelectric fields; (D-F) Colossal flexoresistance in SrTiO₃: (D) I-V curves under varying loading forces, (E) effective resistivity (ρ_eff) as a function of the tip force, and (F) ρ_eff as a function of strain gradient. (A-F) Reproduced with permission^[33]. Copyright 2019, Springer Nature; (G) Concept of flexoelectronics in centrosymmetric semiconductors at a metal-semiconductor interface. (H and I) Experimental flexoelectronic transport measurements in (H) TiO₂ and (I) Nb-doped SrTiO₃ under strain gradients. (G-I) Reproduced with permission^[9]. Copyright 2020, Springer Nature. AFM: Atomic force microscopy; CB: conduction band; VB: valence band.