Stick-Slip Delamination of Monolayer MoS₂ from SiO₂ under Ambient Humidity

Delamination of two-dimensional (2D) materials from substrates plays a key role in 2D material transfer processes and applications in tribology and printing. Here, we studied the delamination of monolayer MoS₂ from a SiO₂ substrate at ambient relative humidity, using atomic force microscopy and force-distance spectroscopy. In contrast to dry conditions, tip retraction at ambient humidity is dominated by capillary forces between the tip and MoS₂ and exhibits an extended force plateau of about 10-15 nm that is decorated by oscillatory sawtooth features. These oscillations indicate a stick-and-slip propagation of a circular delamination front between the MoS₂ and SiO₂ during lifting of the membrane by the tip, when intercalation of water reduces MoS₂-substrate adhesion. This stick-slip delamination process is consistent with depinning from a spatially heterogeneous adhesion landscape, likely influenced by the nanoscale roughness of SiO₂.