Mechanically activated ionic transport across single-digit carbon nanotubes

Fluid and ionic transport at the nanoscale has recently demonstrated a wealth of exotic behaviours^1-14. However, artificial nanofluidic devices^15-18 are still far from demonstrating the advanced functionalities existing in biological systems, such as electrically and mechanically activated transport^19,20. Here, we focus on ionic transport through 2-nm-radius individual multiwalled carbon nanotubes under the combination of mechanical and electrical forcings. Our findings evidence mechanically activated ionic transport in the form of an ionic conductance that depends quadratically on the applied pressure. Our theoretical study relates this behaviour to the complex interplay between electrical and mechanical drivings, and shows that the superlubricity of the carbon nanotubes^4-8,21 is a prerequisite to attaining mechanically activated transport. The pressure sensitivity shares similarities with the response of biological mechanosensitive ion channels^19,20, but observed here in an artificial system. This paves the way to build new active nanofluidic functionalities inspired by complex biological machinery.