Stretch-inactivated ion transport through subnanoporous two-dimensional membranes

In biology, mechanosensitive ion channels facilitate the conversion of mechanical stimuli, such as sound and touch, into electrical signals. Similar functionality in artificial systems was recently predicted in the form of stretch-activated transport through porous 2D membranes. Here we describe an opposite behavior, in which ion transport is inactivated upon stretching a subnanoporous 2D membrane. We explore electrophoretic ion transport through several subnanoporous membranes using molecular dynamics simulations. We demonstrate that aqueous K+ transport decreases by a factor of 3-8 under stretching of order 3%. In contrast, Na+ ions exhibit transport activation by stretching, suggesting ion-dependent activation and inactivation in a single membrane. Our analysis shows that inactivation of K+ transport is caused by a strain-induced repulsive-to-attractive transition in the K+-pore interactions due to alignment of the local energy minima.