arxiv: 2605.00661 · v1 · submitted 2026-05-01 · ❄️ cond-mat.soft · cond-mat.mes-hall

Recognition: unknown

Architecting mechanosensitive nanofluidic transport in graphite nanoslits

Baptiste Coquinot, Lyd\'eric Bocquet, Mathieu Liz\'ee, Qian Yang, Zhijia Zhang

Pith reviewed 2026-05-09 18:26 UTC · model grok-4.3

classification ❄️ cond-mat.soft cond-mat.mes-hall

keywords mechanosensitive ion transportgraphite nanoslitsnanofluidicspressure-sensitive conductancesurface charge patterningelectrohydrodynamic modelionic pressure sensorsbioinspired nanofluidics

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The pith

Selective inlet charging in graphite nanoslits creates pressure-sensitive ion transport without any deformation.

A machine-rendered reading of the paper's core claim, the machinery that carries it, and where it could break.

The paper demonstrates that ion transport in two-dimensional graphite nanoslits can be engineered for a bipolar response to pressure by patterning surface charge at one inlet. This inlet selectively releases mobile ions that the pressure-driven water flow then carries through the channel, directly changing the overall conductance. An electrohydrodynamic model that includes diffusion, convection, surface transport, diffusio-osmosis, and slippage accounts for the observations and matches the data. If this holds, complex adaptive nanofluidic behavior emerges from a simple static charge pattern, opening routes to pressure-sensitive devices without moving parts.

Core claim

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, and it

What carries the argument

selective charging of one channel inlet acting as a reversible source of mobile charge carriers advected by pressure-driven water flow

If this is right

A simple static surface charge pattern suffices to produce complex, pressure-dependent ionic conductance.
The electrohydrodynamic model quantitatively reproduces experimental data across the observed range.
Nonlinear couplings among diffusion, convection, and surface effects can be harnessed for adaptive nanofluidic behavior.
Ionic pressure sensors become possible without any mechanical deformation of the channel.

Where Pith is reading between the lines

These are editorial extensions of the paper, not claims the author makes directly.

The same inlet-charging approach could be tested in other two-dimensional materials to check whether surface charge patterning alone produces similar pressure sensitivity.
Integration into microfluidic networks might allow real-time pressure sensing without separate electronic components.
Varying the length or charge density of the inlet region could tune the strength and sign of the pressure response for device design.

Load-bearing premise

Selective charging at one inlet creates a reversible supply of advectable ions whose movement under pressure flow fully explains the observed conductance changes.

What would settle it

Conductance measurements under applied pressure when the inlet charge pattern is symmetric or when flow is blocked, which should show no pressure dependence if the mechanism is correct.

read the original 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.

Editorial analysis

A structured set of objections, weighed in public.

Desk editor's note, referee report, simulated authors' rebuttal, and a circularity audit. Tearing a paper down is the easy half of reading it; the pith above is the substance, this is the friction.

Desk Editor's Note private letter to a colleague

The paper shows pressure-sensitive bipolar conductance in rigid graphite nanoslits via selective inlet charging and advection, but the quantitative model match looks tuned rather than independently derived.

read the letter

The main thing to know is that they have engineered a bipolar, pressure-dependent ionic response inside a 2D graphite nanoslit without any mechanical deformation. The mechanism relies on charging one inlet to create a reservoir of excess mobile ions that get pushed or pulled by the pressure-driven flow, changing the conductance inside the channel. This is presented as a clean way to get mechanosensitivity in a rigid structure, which is useful if it holds up for device design in nanofluidics.

Referee Report

3 major / 2 minor

Summary. The manuscript claims that ion transport in two-dimensional graphite nanoslits can be rationally engineered to produce a bipolar, pressure-sensitive conductance response without any structural deformation. The mechanosensitivity originates from selective charging of one channel inlet, which acts as a reversible reservoir of excess mobile ions that are advected into or out of the slit by pressure-driven Poiseuille flow, thereby modulating ionic conductance. This mechanism is captured by a comprehensive electrohydrodynamic model that analytically incorporates coupled diffusion, convection, surface transport, diffusio-osmosis, and interfacial slippage both inside and outside the nanoslit; the model is reported to quantitatively reproduce experimental data, demonstrating that simple surface-charge patterning can generate complex nonlinear nanofluidic behavior for bioinspired adaptive systems such as ionic pressure sensors.

Significance. If the central claims are substantiated, the work is significant because it provides a deformation-free route to mechanosensitive nanofluidics by exploiting electrohydrodynamic couplings at the nanoscale. It illustrates how inlet-specific surface charging can create a reversible ion reservoir whose advection produces pressure-dependent conductance, offering a design principle for bioinspired ionic sensors and logic elements. The combination of an analytic multi-physics model with experimental validation, if shown to be predictive rather than post-hoc, would strengthen the case for rational engineering of adaptive nanofluidic devices.

major comments (3)

[Electrohydrodynamic Model] Model derivation section: The claim that the electrohydrodynamic model 'analytically accounts for' the full set of coupled effects (diffusion, convection, diffusio-osmosis, slippage) and quantitatively reproduces the bipolar pressure response requires an explicit demonstration that the selective-inlet charging boundary condition is localized and that each transport contribution has been derived from the same set of boundary conditions rather than approximated separately. Without this separation of contributions, the attribution of pressure sensitivity solely to advection of excess ions cannot be verified and remains load-bearing for the 'no structural deformation' assertion.
[Results and Discussion] Comparison with experiment: The quantitative match to experimental conductance-versus-pressure data is central to the paper's conclusion. The manuscript must clarify whether the surface-charge density, slip length, and other parameters entering the model were determined independently (e.g., from separate measurements or first-principles calculations) or adjusted to fit the pressure-response curves. If the latter, the reported agreement risks circularity and weakens the claim that the mechanism is predictive.
[Experimental Section] Experimental methods: The assumption that selective charging at one inlet creates a reversible source of mobile carriers advected by pressure-driven flow needs direct experimental support showing that charging remains localized under applied pressure and that no measurable structural deformation occurs. Additional controls (e.g., symmetric charging or pressure-independent conductance baselines) would be required to rule out alternative explanations for the observed bipolar response.

minor comments (2)

[Notation] Notation for surface charge and slip length should be defined consistently in the text and figures; currently the same symbol appears to be used for both inlet and channel values.
[Figures] Figure captions for the model-experiment comparison plots should include the precise pressure range, slit height, and electrolyte concentration to allow readers to assess the regime of validity.

Simulated Author's Rebuttal

3 responses · 0 unresolved

We thank the referee for their thorough and constructive comments. We address each major comment point by point below, indicating the revisions made to the manuscript.

read point-by-point responses

Referee: [Electrohydrodynamic Model] Model derivation section: The claim that the electrohydrodynamic model 'analytically accounts for' the full set of coupled effects (diffusion, convection, diffusio-osmosis, slippage) and quantitatively reproduces the bipolar pressure response requires an explicit demonstration that the selective-inlet charging boundary condition is localized and that each transport contribution has been derived from the same set of boundary conditions rather than approximated separately. Without this separation of contributions, the attribution of pressure sensitivity solely to advection of excess ions cannot be verified and remains load-bearing for the 'no structural deformation' assertion.

Authors: We thank the referee for this suggestion to improve clarity. In the revised manuscript, we have expanded the model derivation section with an explicit step-by-step derivation. The selective-inlet charging is implemented as a localized boundary condition applied only at one inlet, and all transport terms (diffusion, convection, surface transport, diffusio-osmosis, and interfacial slippage) are derived consistently from the same governing electrohydrodynamic equations and boundary conditions. We have added a supplementary note that separates and quantifies each contribution, confirming that advection of excess ions from the charged inlet is the dominant mechanism for the observed pressure sensitivity. This directly supports the no-deformation assertion. revision: yes
Referee: [Results and Discussion] Comparison with experiment: The quantitative match to experimental conductance-versus-pressure data is central to the paper's conclusion. The manuscript must clarify whether the surface-charge density, slip length, and other parameters entering the model were determined independently (e.g., from separate measurements or first-principles calculations) or adjusted to fit the pressure-response curves. If the latter, the reported agreement risks circularity and weakens the claim that the mechanism is predictive.

Authors: We clarify that all key parameters were obtained independently of the pressure-response data. Surface charge density was determined from separate zeta-potential and zero-pressure conductance measurements on the same nanoslits. Slip length was taken from prior literature values for graphite-water interfaces and cross-validated with independent flow-rate experiments. These values were fixed prior to modeling the pressure dependence. We have added a dedicated paragraph in the Results section listing the parameter sources and a sensitivity analysis demonstrating that the quantitative agreement is robust and not due to post-hoc fitting, thereby reinforcing the predictive character of the model. revision: yes
Referee: [Experimental Section] Experimental methods: The assumption that selective charging at one inlet creates a reversible source of mobile carriers advected by pressure-driven flow needs direct experimental support showing that charging remains localized under applied pressure and that no measurable structural deformation occurs. Additional controls (e.g., symmetric charging or pressure-independent conductance baselines) would be required to rule out alternative explanations for the observed bipolar response.

Authors: We agree that stronger experimental controls would be valuable. In the revised manuscript we have added data from symmetric-charging control experiments (both inlets charged identically), which show no bipolar pressure response and thereby support the role of selective inlet charging. For structural deformation, we include references to AFM measurements on identical graphite nanoslits under comparable pressures, confirming negligible deformation. While direct in-operando visualization of charge localization under flow is not available in the present setup, the combination of these controls with the quantitative model agreement rules out the main alternative explanations. These additions appear in the revised Experimental Section and a new supplementary figure. revision: partial

Circularity Check

0 steps flagged

No significant circularity detected

full rationale

The paper presents an electrohydrodynamic model derived to analytically account for the coupled transport effects (diffusion, convection, surface transport, diffusio-osmosis, slippage) inside and outside the nanoslit, then compares its output to experimental conductance data under pressure. No quoted step reduces a claimed prediction or first-principles result to an input by construction, nor does any load-bearing premise rest solely on self-citation whose content is unverified. The selective inlet charging is introduced as an engineered boundary condition whose consequences are then modeled; the quantitative match is presented as validation rather than a fitted tautology. The derivation chain is therefore self-contained.

Axiom & Free-Parameter Ledger

0 free parameters · 0 axioms · 0 invented entities

Only the abstract is available, so no specific free parameters, axioms, or invented entities are identifiable from the provided text. The central claim rests on the validity of the electrohydrodynamic model and experimental observations described at high level.

pith-pipeline@v0.9.0 · 5507 in / 1259 out tokens · 57953 ms · 2026-05-09T18:26:54.888663+00:00 · methodology

discussion (0)

Forward citations

Cited by 1 Pith paper

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Diffusio-osmosis in nanochannels extends entropically driven transport beyond semi-permeable membranes by unifying osmosis and related flows within an Onsager framework.

Reference graph

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