Architecting mechanosensitive nanofluidic transport in graphite nanoslits

TL;DR

This paper demonstrates that ion transport in graphite nanoslits can be engineered to be pressure-sensitive through surface charge patterning, enabling adaptive nanofluidic systems without structural deformation.

Contribution

It introduces a rational design for mechanosensitive ion transport in nanoslits using surface charge control, supported by a comprehensive electrohydrodynamic model.

Findings

Experimental data matches the theoretical model.

A simple surface charge pattern induces pressure-dependent conductance.

The mechanism enables design of adaptive, bioinspired nanofluidic sensors.

Abstract

Mechanosensitive ion transport plays a central role in enabling living systems to perceive and adapt to their environment through the deformation of soft, embedded ion channels. In this work, we demonstrate that ion transport within a two-dimensional graphite nanoslit can be rationally engineered to achieve a bipolar, pressure-sensitive response without any structural deformation. The mechanosensitivity arises from the selective charging of one channel inlet, which acts as a reversible source of mobile charge carriers. These excess-ions can then be advected in or out of the channel by the pressure-driven water flow, thereby modulating the ionic conductance. This mechanism is captured through a comprehensive electrohydrodynamic model that analytically accounts for coupled diffusion, convection, surface transport, diffusio-osmosis, and interfacial slippage, both inside and outside the nanoslit. The theoretical framework quantitatively reproduces the experimental data, showing that a simple surface charge pattern can give rise to complex, pressure-dependent conductance. These findings reveal how rich nonlinear couplings at the nanoscale can be harnessed to design adaptive, bioinspired nanofluidic systems, exemplified here by ionic pressure sensors.