Silicon Carbide-Gated Nanofluidic Membrane for Active Control of Electrokinetic Ionic Transport

Manipulation of ions and molecules by external control at the nanoscale is highly relevant to biomedical applications. We report a biocompatible electrode-embedded nanofluidic channel membrane designed for electrofluidic applications such as ionic field-effect transistors for implantable drug-delivery systems. Our nanofluidic membrane includes a polysilicon electrode electrically isolated by amorphous silicon carbide (a-SiC). The nanochannel gating performance was experimentally investigated based on the current-voltage (I-V) characteristics, leakage current, and power consumption in potassium chloride (KCl) electrolyte. We observed significant modulation of ionic diffusive transport of both positively and negatively charged ions under physical confinement of nanochannels, with low power consumption. To study the physical mechanism associated with the gating performance, we performed electrochemical impedance spectroscopy. The results showed that the flat band voltage and density of states were significantly low. In light of its remarkable performance in terms of ionic modulation and low power consumption, this new biocompatible nanofluidic membrane could lead to a new class of silicon implantable nanofluidic systems for tunable drug delivery and personalized medicine.

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

A versatile ionic field effect transistor (IFET) which has an ambipolar function for manipulating molecules regardless of their polarity was developed for the operation at a wide range of electrolytic concentrations (10−5 M–1 M).

Polyaniline Protonation and Deprotonation Process as the Main Mechanism for Ionic Field Effect Sensors

ABSTRACTIn this work, Polyaniline (PANI) was used as a sensing film for pH measures due to its characteristic of switching protonation states under acid and alkaline solutions. Equally produced films had their sensitivity (electric response versus pH) measured before and after being under the influence of a constant electric potential (from 3.5 to 6 V, one for each film) for the analysis on how the electric potential influenced the sensitivity. Then, the protonation caused by the application of the first potential was reversed by applying a constant 5 V reverse potential and the sensitivity was then evaluated again. The results show, on average, a constant relation between intensity of protonation and the potential applied and that the process of protonation is reversible by applying a higher opposite potential then the protonation one.