Mechanosensitive conductance of single-digit carbon nanotubes

Despite the recent advances in the conception of artificial devices with nanometre scale confinements, these are still far from the advanced functionalities existing in biological systems, such as ionic pumping, or electrically and mechanically activated transport. However the unusual properties of carbon nanotubes (CNT) in term of water and ion transport open new possibilities for the development of advanced iontronic functions.
In this work [1], we investigate the ionic transport through 2 nm-radius individual multiwalled CNT under the combination of mechanical and electrical forcings. Our findings evidence mechanically activated ionic transport, which takes the form of an ionic conductance which depends quadratically on the applied pressure. This behaviour is rationalized theoretically in terms of the complex interplay between electrical and mechanical drivings, showing that ultra-low friction of water on carbon nanotubes surfaces is a prerequisite to attain mechanically activated transport. The quadratic pressure dependent conductance is reminiscent of similar reports in biological mechanosensitive ion channels, paving the way to new active nanofluidic functionalities inspired by the complex biological machinery.

[1] Marcotte et al., Nature Materials 19,1057-1061 (2020)