Nanotechnology and Nanomaterials for Improving Neural Interfaces

Abstract

A successful biomaterial–neural tissue interface should demonstrate biocompatibility, cytocompatibility, the ability to integrate properly within neural tissues, and the prolonged maintenance of desired electrical properties. Neural electrodes implanted in vivo often experience degradation of these properties due to implant micromotion, mechanical mismatch, an extensive foreign‐body response, and the formation of glial scar tissue that interfere with signal transmission. However, recent advances in nanotechnology and nanomaterials show great promise to address these problems due to their biologically inspired surface features and enhanced electrical properties. This review will discuss how nanomaterials and nanotechnology are being used to fabricate advanced neural electrodes that demonstrate greater bio‐integration properties, enhanced prolonged electrical properties, and an improved signal specificity down to the single molecule range. First, an overview of current biomaterial–neural tissue interface technology is provided, followed by an examination of conventional and newly developed micro‐ and nano‐fabrication methodologies. Nanomaterials that have shown the most promise for neural interfacial applications are then discussed, including carbon nanomaterials, conductive polymers, and hybrid nanomaterials. The purpose of this review is to describe recent advances in nanotechnology for improved biomaterial–neural tissue interfaces, and identify their advantages and disadvantages from a researcher's perspective.

Preparation of carboxylic graphene oxide‐composited polypyrrole conduits and their effect on sciatic nerve repair under electrical stimulation

“…The functionalized graphene materials, such as carboxylic graphene oxide (C‐GO), were applied in biomedical field, especially carboxyl groups of C‐GO led to its better surface hydrophilicity (Shen, Zhang, Liu, & Zhang, ; Tobias, Paul, Maria‐Luisa, & Navas, ). Furthermore, the addition of graphenes into CPs could not only improve the materials conductivity, but also enhance their electrochemical stability (Wang et al, ).…”

Soft and Ion‐Conducting Materials in Bioelectronics: From Conducting Polymers to Hydrogels

“…With the miniaturization of bioelectronic devices, precise stimulation down to the single neuron level can be achieved with smaller microelectrodes . Smaller metal electrodes require higher voltage to provide the same amount of current and stimulation due to increased impedance and decreased capacitance . The electrolyte environment that surrounds cells and tissue is very sensitive to voltage, and damage to both the tissue and the electrode may occur above a safe voltage threshold.…”

“…[10] amount of current and stimulation due to increased impedance and decreased capacitance. [12,35] The electrolyte environment that surrounds cells and tissue is very sensitive to voltage, and damage to both the tissue and the electrode may occur above a safe voltage threshold. This damage includes local heat, pH change, electrode degradation, and the generation of highly reactive chemical species.…”

Synaptic Communication Engineering for Future Cognitive Brain–Machine Interfaces

“…The ability to scale the electronic devices to the size of a typical neuron is challenging. Applying nanotechnology and nanomaterials may give us the ability to produce miniature cognitive BMIs with improved electrical and mechanical properties [121]. Nanotechnology has already drastically improved fabrication methods of neural electrodes (nanoelectrodes, nanoelectrode arrays, and nanoelectrode ensembles) demonstrating greater bio-integration properties, enhanced prolonged electrical properties, and an improved signal specificity.…”