Field-effect reconfigurable nanofluidic ionic diodes

Abstract

several types of nanofluidic devices based on nanopores and nanochannels have been reported to yield ionic current rectification, with the aim to control the delivery of chemical species in integrated systems. However, the rectifying properties obtained by existing approaches cannot be altered once the devices are made. It would be desirable to have the ability to modulate the predefined properties in situ without introducing external chemical stimuli. Here we report a field-effect reconfigurable nanofluidic diode, with a single asymmetrically placed gate or dual split-gate on top of the nanochannel. The forward/reverse directions of the diode as well as the degrees of rectification can be regulated by the application of gate voltages. Compared with the stimuli-responsive tuning of the rectification properties, the electrostatic modulation offers a fully independent and digitally programmable approach for controlling the preferential conduction of ions and molecules in fluids. This device would serve as a building block for largescale integration of reconfigurable ionic circuits.

Field effect modulated nanofluidic diode membrane based on Al2O3/W heterogeneous nanopore arrays

“…7,10,13 In such a configuration a top gate electrode is used to modulate ionic transport through the nanochannels for nanofluidic transistors. [20][21][22][23] However, planar nanochannels are generally long with small cross section and therefore have very small throughput of ionic current.…”

Sub-10 nm transparent all-around-gated ambipolar ionic field effect transistor

“…13,16 We defined the threshold voltage V th as required gate voltage to regulate the zero-polarity of the nanochannel. When gate voltage was higher than V th , the nanochannel had the positive polarity and vice versa.…”

“…14,17,18 While they had easy-fabrication and relatively high uniformity, these materials had high surface charge density which led to a unipolar behavior. [11][12][13][14][15][16] The reason why the unipolar behavior occurs is that induced surface potential by gate voltage cannot overcome a polarity of inherent surface potential. Due to this characteristic, a traditional IFET can only control the same polarity of charged species with the surface charge of the nanochannel.…”

Thermally modulated biomolecule transport through nanoconfined channels

“…In the past years, nanopore-based device is attracting more and more attentions for its potential applications in selective molecular separation [1,2], biosensing [3,4], energy storage [5,6], controlled release [7,8], drug delivery [9,10], nanofluidics, and nanoelectronics [11][12][13][14]. It is generally believed that the premise of this method is how to obtain proper nanopores and how to design effective fluidic device.…”