Direct Growth of Carbon Nanotubes on New High-Density 3D Pyramid-Shaped Microelectrode Arrays for Brain-Machine Interfaces.

Bahareh Ghane Motlagh,Mohamad Sawan,M Choueib ,Alireza Hajhosseini Mesgar,Hasanuzzaman Hasanuzzaman

doi:10.3390/mi7090163

Abstract

Silicon micromachined, high-density, pyramid-shaped neural microelectrode arrays (MEAs) have been designed and fabricated for intracortical 3D recording and stimulation. The novel architecture of this MEA has made it unique among the currently available micromachined electrode arrays, as it has provided higher density contacts between the electrodes and targeted neural tissue facilitating recording from different depths of the brain. Our novel masking technique enhances uniform tip-exposure for variable-height electrodes and improves process time and cost significantly. The tips of the electrodes have been coated with platinum (Pt). We have reported for the first time a selective direct growth of carbon nanotubes (CNTs) on the tips of 3D MEAs using the Pt coating as a catalyzer. The average impedance of the CNT-coated electrodes at 1 kHz is 14 kΩ. The CNT coating led to a 5-fold decrease of the impedance and a 600-fold increase in charge transfer compared with the Pt electrode.

Highlights

One of the major goals of the emerging field of neurotechnology is restoration of nervous system disorders
Neuroprosthetic devices that interface with the central nervous system (CNS), called brain-machine interfaces (BMI), enable direct communication with still-functioning parts of the neural pathways and have the potential to restore various lost functions of patients with vision impairment, epilepsy, Parkinson’s disease, or depression [1,2]
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Summary

Introduction

One of the major goals of the emerging field of neurotechnology is restoration of nervous system disorders. Neuroprosthetic devices that interface with the central nervous system (CNS), called brain-machine interfaces (BMI), enable direct communication with still-functioning parts of the neural pathways and have the potential to restore various lost functions of patients with vision impairment, epilepsy, Parkinson’s disease, or depression [1,2]. For electrical stimulation and recording, electrodes with a multi-dimensional geometry, high selectivity and density, as well low impedance, are required. Developing fabrication methods that improve the electrodes electrical and mechanical characteristics are essential. The first architecture—in-plane microelectrodes—was developed at the University of Michigan. In these MEAs, microelectrode contacts are patterned along the shanks. This technology provides a high density of contacts; the shanks cause

Methods

Results

Conclusion