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Updated: Jul 16, 2026

Electric-field Control of Electronic States in WS2 Nanodevices by Electrolyte Gating
Published on: April 12, 2018
Electrostatic gating of a nanometer water channel
Jingyuan Li1, Xiaojing Gong, Hangjun Lu
1Department of Physics, Zhejiang University, Hangzhou 310027, China.
A single external charge can precisely control water flow through carbon nanotubes, acting as a gate. This precise control is effective within a short distance, offering potential for biological water channel applications.
Area of Science:
- Nanotechnology
- Biophysics
- Physical Chemistry
Background:
- Biological water channels facilitate selective water transport across cell membranes.
- Understanding nanoscale water transport is crucial for developing artificial channels.
- Single-walled carbon nanotubes (SWNTs) offer a model system for studying confined water flow.
Purpose of the Study:
- To investigate the effect of a mobile external charge on water permeation through a SWNT.
- To determine the gating mechanism and sensitivity of a designed nanopore to external charges.
- To explore the potential biological implications of charge-controlled water transport.
Main Methods:
- Molecular dynamics simulations were employed to model water permeation.
- The interaction between an external charge and water molecules within the SWNT was analyzed.
- The critical distance for charge influence on water flux was calculated.
Main Results:
- A single external charge (+1.0e) demonstrated excellent on-off gating behavior for water flow.
- The SWNT nanopore was sensitive to charges within 0.85 Å and resistant to noise from distant charges.
- Water flux decayed exponentially with decreasing charge distance, dominated by local water molecule interactions.
Conclusions:
- External charge proximity dictates water permeation in SWNTs, with a critical distance of 0.85 Å.
- This charge-controlled gating mechanism offers high sensitivity and noise resistance.
- Findings suggest potential applications in artificial membrane water channels mimicking biological systems.
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