Mechanically activated ionic transport across single-digit carbon nanotubes

TL;DR

This study demonstrates mechanically activated ionic transport in 2 nm carbon nanotubes, revealing pressure-dependent conductance and biological-like mechanosensitivity, advancing nanofluidic device functionalities.

Contribution

It introduces the first artificial system showing pressure-sensitive ionic conductance similar to biological channels, combining mechanical and electrical stimuli in CNTs.

Findings

Ionic conductance depends quadratically on applied pressure.

Superlubricity of CNTs is essential for activation.

Biological-like mechanosensitivity observed in artificial nanofluidics.

Abstract

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