# Development of carbon-nanotube fiber based microelectrode array for neuroscience

> **NIH NIH R21** · UNIVERSITY OF CINCINNATI · 2022 · $431,394

## Abstract

PROJECT SUMMARY/ABSTRACT
The objective of this proposal is to develop, evaluate the potential of Carbon Nanotube (CNT) fibers
Microelectrode Arrays (MEAs) and test their performance in-vivo by inserting them in the visual cortex
of rats in acute and chronic settings. Its novelty relies on the reduced diameter, super-hydrophilic
coating nature of the CNT fibers, and takes advantage of the chemical inertness, flexibility and large
surface area of CNTs. Additional feature of these proposal is the hexagonal packing of 7 CNT fibers
into ~50 µm strands to provide the required stiffness for insertion, and subsequent unraveling into 7
individual electrodes upon insertion and interaction with water. Proposed approach will allow to pack
112 electrodes into a 4x4 array, and will be able to connect to metal contact board produced with
traditional lithography. Currently, most commands emitted from the brain require electrical currents
transported through nerves and tissue to elicit cognitive, sensory, visceral, and motor functions.
Unfortunately, these connection paths are often perturbed due to traumatic or degenerative diseases
causing complete loss of function. Multiple brain diseases like epilepsy and Parkinson's require
microelectrode stimulation as part of the treatment and recovery. Most current technology relies on
metal-, metal oxide or silicon-based electrodes that have a mechanical mismatch and are considered
foreign by cells and neurons causing adverse reactions through inflammatory responses, biofouling
and scar tissue formation as they try to encapsulate the electrode. Moreover, metals employed as
electrodes have: significantly smaller surface area, larger impedance, and reduced charge injection
limit (CIL). To solve these electrode deficiencies currently employed in neural stimulation and recording,
this team has developed unidirectional, biocompatible, densely-packed CNT fiber microelectrodes that
to this date show impressive CIL (15.6 mC/cm2), fast electron transport, and lower impedance than
metals. Surprisingly, these CNT fibers can be assembled up to 16 m/s linear speeds, offering great
potential towards scalability. We expect to demonstrate the potential of our fiber for long them
stimulation and recording, as well as compare their performance as MEAs to the state-of-the-art carbon
fiber, and iridium based MEAs.

## Key facts

- **NIH application ID:** 10527492
- **Project number:** 1R21NS125461-01A1
- **Recipient organization:** UNIVERSITY OF CINCINNATI
- **Principal Investigator:** Noe Alvarez
- **Activity code:** R21 (R01, R21, SBIR, etc.)
- **Funding institute:** NIH
- **Fiscal year:** 2022
- **Award amount:** $431,394
- **Award type:** 1
- **Project period:** 2022-06-01 → 2025-05-31

## Primary source

NIH RePORTER: https://reporter.nih.gov/project-details/10527492

## Citation

> US National Institutes of Health, RePORTER application 10527492, Development of carbon-nanotube fiber based microelectrode array for neuroscience (1R21NS125461-01A1). Retrieved via AI Analytics 2026-05-27 from https://api.ai-analytics.org/grant/nih/10527492. Licensed CC0.

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