Moiré-induced modulation of out-of-plane elasticity in twisted hBN.

Abstract

Moiré superlattices in twisted van der Waals materials provide a versatile platform where interlayer interactions generate periodic variations of atomic registry and local physical properties. Here, we reveal that these moiré patterns also modulate the effective out-of-plane elastic response of twisted hexagonal boron nitride (t-hBN). Using contact-mode atomic force microscopy and force-spectroscopy nanomechanics, we show that the effective out-of-plane Young's modulus exhibits a reproducible modulation by up to 10% across a single moiré unit cell, with softer AA and saddle-point regions and stiffer AB/BA domains. The resulting contrast produces a measurable topographic modulation even under ambient conditions, enabling the moiré superlattice to be visualized as a manifestation of its elastic landscape. These findings demonstrate that the effective out-of-plane elastic response is modulated by the moiré superlattice, extending the understanding of twisted two-dimensional materials beyond their electronic and optical properties and opening routes toward mechanically tunable moiré systems.