Nanofludic field effect transistor based on surface charge modulated nanochannel

A field-effect transistor device comprising:

• a reservoir separated into two parts, said reservoir comprising an insulating material;
• a membrane that separates the reservoir into the two parts, said membrane comprising three layers:
• two electrically insulating layers;
• and
• an electrically conductive gate disposed between the two electrically insulating layers, wherein said electrically conductive gate comprises a surface charge polarity different from at least one of the two electrically insulating layers when they are in contact with an ionic solution;
• a nanochannel through the membrane that connects the two parts of the reservoir;
• said ionic solution introduced into the nanochannel for filling the reservoir to produce an ionic channel, producing a surface-charge-modulated ionic channel through the membrane, wherein the modulated surface charge is due to different surface properties of the two electrically insulating layers and the electrically conductive gate;
• a drain electrode;
• a source electrode;
• and
• a voltage applied between the source and drain electrodes and a voltage applied on the electrically conductive gate layer in the membrane, turning on an ionic current through the ionic channel;
• wherein the voltage on the electrically conductive gate gates transportation of ions through the ionic channel;
• and
• wherein the nanochannel comprises a diameter less than twice of a Debye length of the ionic solution, which ranges from 0.3 nm to 10 nm, depending on ionic strength of said ionic solution.