Stacked layers of molybdenum disulfide slide past each other with almost zero resistance by flowing like a liquid rather than moving as solid sheets.
April 24, 2026
Original Paper
Domain-Wall-Mediated Ultralow-Barrier Sliding and Pinning in Ferroelectric Moiré Superlattices Revealed by Machine Learning
arXiv · 2604.20277
The Takeaway
MoS2 moiré superlattices achieve ultra-low-barrier sliding through a collective reconstruction of their internal domain walls. Instead of the atoms grinding against each other, the boundaries between different crystal regions move in a coordinated wave. This mechanism allows the material to slide at room temperature with almost no energy input. Traditional friction models predicted much higher barriers for these layered materials. This discovery could lead to superlubricated machine parts that never wear out and require zero oil or grease.
From the abstract
Sliding ferroelectrics built from stacked nonpolar monolayers enable out-of-plane polarization and unconventional switching via interlayer sliding, yet the microscopic sliding dynamics remain unclear. Using machine-learning molecular dynamics, we reveal spontaneous thermally driven interlayer sliding in ferroelectric MoS2 moiré superlattices, with relative velocities on the order of 1 m/s at 300 K. Instead of rigid translation of the entire bilayer, the motion appears as a global drift of the mo