Switchable tribology of ferroelectrics

Abstract

Switchable tribological properties of ferroelectrics offer an alternative route to visualize and control ferroelectric domains. Here, we observe the switchable friction and wear behavior of ferroelectrics using a nanoscale scanning probe—down domains have lower friction coefficients and show slower wear rates than up domains and can be used as smart masks. This asymmetry is enabled by flexoelectrically coupled polarization in the up and down domains under a sufficiently high contact force. Moreover, we determine that this polarization-sensitive tribological asymmetry is widely applicable across various ferroelectrics with different chemical compositions and crystalline symmetry. Finally, using this switchable tribology and multi-pass patterning with a domain-based dynamic smart mask, we demonstrate three-dimensional nanostructuring exploiting the asymmetric wear rates of up and down domains, which can, furthermore, be scaled up to technologically relevant (mm–cm) size. These findings demonstrate that ferroelectrics are electrically tunable tribological materials at the nanoscale for versatile applications.

Recent progress of organic artificial synapses in biomimetic sensory neural systems

“…This spontaneous polarization arises from the internal lattice structure asymmetry of ferroelectric materials. 104 Consequently, the resistance state of the device can be controlled by applying an electric field to manipulate the arrangement of dipoles within the ferroelectric material. 103 In recent years, ferroelectric polymers have emerged as a highly promising non-volatile memory solution, attributed to their inherent polarizability and high dielectricity.…”

Observing and Modeling the Wear Process of Heterogeneous Interface

“…The models also did not take into account the effects of the asperity’s shape and the interface’s orientation. With the development of nanotechnology in the past three decades, atomic force microscopy (AFM) has gradually shown its advantages in the field of microscopic wear, − providing the possibility to study the wear process at individual interface. However, AFM can only obtain information on the sample surface, and the interfaces buried in the matrix cannot be observed, which limits its application.…”