Ion-electron coupling-enabled mechanical ion transistor with ultralow subthreshold swing

Area of Science:

• Materials Science
• Biophysics
• Nanotechnology

Background:

• Biological mechanosensitive (BMS) ion channels exhibit sharp on-off states crucial for biological functions.
• Replicating these distinct states in artificial structures for applications remains a significant challenge.

Purpose of the Study:

• To engineer an artificial mechanical ion transistor that mimics the sharp switching behavior of BMS ion channels.
• To explore applications in ultrasensitive detection and precise ion transport control.

Main Methods:

• Fabrication of graphene nanochannels integrated with an electrostatic gating system.
• Characterization of streaming current response to applied pressure.
• Analysis of ionic Coulomb blockade and ion-electron coupling effects.

Main Results:

• The mechanical ion transistor demonstrated a stepwise streaming-current versus pressure response.
• Achieved an ultralow subthreshold swing (4.8 millibars per decade), surpassing current artificial structures and most BMS channels.
• Observed threshold pressure and current oscillation, attributed to ionic Coulomb blockade.

Conclusions:

• The developed mechanical ion transistor effectively replicates the ultrasensitive switching of BMS channels.
• The findings provide insights into BMS channel mechanisms and enable new routes for ion transport control.
• Potential applications include water filtration, energy harvesting, and neuromorphic sensing.