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

Abstract

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.

Comprehensive Analysis of Electrostatic Gating in Nanofluidic Systems

“…Dielectric materials with higher κ have thus been used to reduce these currents and improve gating performance . SiC, for instance, not only has a higher κ but also offers biocompatibility and chemical inertness, , which render it ideal for biomedical applications. , However, complexity in the deposition methods of SiC may lead to defects that can compromise its electrical insulation properties, especially for very thin films. , …”

“…54,55 However, complexity in the deposition methods of SiC may lead to defects that can compromise its electrical insulation properties, especially for very thin films. 56,57 4.3. Native Surface Charge Influence on Electrostatic Gating.…”

Voltage-gated nanofluidic devices for protein capture, concentration, and release

“…21,27 These gates provide a transverse surface potential and subsequent electric field in addition to a streamwise potential difference driving the bulk electrokinetic flow. Such gate electrodes have been used to modulate the flow of ions 31 or proteins in nanochannels. 21 The configuration of a streamwise driving potential accompanied by an additional gate electrode is geometrically analogous to solid-state electronic transistors.…”

Space Medicines for Space Health

“…Nano-implantable medical devices are cutting-edge solutions for controlled drug delivery in the medical field. , A study facilitated by the ISS U.S. National Laboratory treated muscle loss with continuous delivery of a low dose of medicine to a patient system through a tiny implantable unit with a channel that is in the nanometer range (see Figure ). The concept was tested on healthy mice in a real space environment in the Rodent Research 6 mission.…”