Low-force pulse switching of ferroelectric polarization enabled by imprint field.

Abstract

Beyond conventional electrical modulation, flexoelectricity enables mechanical control of ferroelectric polarizations, offering a pathway for tactile-responsive ferroelectric systems. However, mechanical polarization switching typically requires substantial static threshold forces to overcome the significant energy barrier, resulting in material fatigue and slow response that compromises reliability and hinders practical applications. In this work, we address these challenges by introducing an imprint field through asymmetric electrostatic boundary design with distinct work functions. This built-in electric field stabilizes the energy landscape, effectively lowering the polarization switching barrier. Subsequently, nonvolatile polarization switching with a low threshold force of 12 nN·nm^-1 is achieved in CuInP₂S₆ without material damage. Surpassing the limitations of slow static force controls, our work marks the first experimental demonstration of fast mechanical control of polarization switching with 4 millisecond-long low force pulses. To further highlight the potential of this rapid, low-force mechanical control, we propose a van der Waals heterostructured mechanically gated transistor with asymmetric electrostatic boundary, which exhibits gate force pulses-controlled multi-level, nonvolatile conductance states. Our findings establish a paradigm for next-generation ferroelectric electronics that integrate responsiveness to mechanical stimuli.