Carbon Nanotube-Coated Electrodes Improve Brain Readouts

August 12, 2008 By Laura Mgrdichian feature
Carbon Nanotube-Coated Electrodes Improve Brain Readouts

Enlarge

A scanning electron microscope image of a metal electrode (dark region in center of image) coated with carbon nanotubes.

A research group has significantly improved the quality of brain-function measurements by coating metal neural electrodes with carbon nanotubes. Their work could potentially allow scientists to learn more about brain diseases that are based on electrical impulse malfunctions, such as Parkinson's and epilepsy.

One limitation of current machines used to record brain signals are the electrodes: They have a natural resistance to electric current, called impedance, which compromises their ability to produce sensitive readouts. The impedance also makes the machines less effective at putting out charge when they are being used to simulate brain-cell activity via neurons in culture.

Coating the electrodes with carbon nanotubes, which have excellent electrical properties, offers a solution to both problems, discovered Edward Keefer, of the University of Texas Southwestern Medical School, and colleagues from the Texas Scottish Rite Hospital for Children, Vanderbilt University, and the University of North Texas.

“Modulation of brain activity to provide symptomatic relief from growing number of diseases such as Parkinson’s, depression, and epilepsy has become the treatment of choice when all other options fail," Keefer told PhysOrg.com. "The interface between the cells of the brain and the surface of the implanted electrode determines whether these treatments work or not. By coating electrode surfaces with carbon nanotubes, we can improve the efficiency of this cell-electrode interface by one-thousand times or even more.”

Keefer compared the improvement in nanotube-coated electrodes over standard electrodes to the difference between watching your favorite show on a 13-inch black-and-white television with a broken antenna or a brand-new 60-inch, high-definition, satellite-fed model.

"For an electrophysiologist, that is the difference the nanotube-coated electrodes make in what we can see on our oscilloscopes," he said.

The electrodes they tested were commercial varieties made of tungsten and stainless steel wire, which are thin and sharp. In two animal samples—the motor cortex of rats under anaesthesia and the visual cortex of awake rhesus macaque monkeys—the group took readouts with a nanotube-coated electrode and a non-coated electrode, and compared the results.

In both cases, the coated electrodes produced much better readings. The performance was further enhanced when the group used a coating made of a combination of carbon nanotubes and a conducting polymer material.

Additionally, scanning electron microscope images showed that the coating on the electrodes used for the monkeys had not been damaged by the tough outer brain layer, called the dura mater.

Besides performance, the coated electrodes have other advantages. Scientists have already documented the properties and performance of metal-coated electrodes used in other applications, such as electronics, and nanotubes appear to be nicely biocompatible. For example, scientists have had success using carbon nanotube substrates as supports for the growth of neurons.

Nanotube-coated electrodes are compatible with existing brain-machine devices, so that new equipment wouldn't need to be developed to use them.

While the group's tests were a success, nanotube-coated electrodes are not yet ready for humans. There is much more to learn, including how the coated electrodes hold up over long exposure to neural tissue.

Citation: Keefer, E. W., Botterman, B. R., Romero, M. I., Rossi, A. F. & Gross, G. W. Nature Nanotech. 3, 434-439 (2008).

Copyright 2008 PhysOrg.com.
All rights reserved. This material may not be published, broadcast, rewritten or redistributed in whole or part without the express written permission of PhysOrg.com.

4.3 /5 (23 votes)  

Filter


Move the slider to adjust rank threshold, so that you can hide some of the comments.


Display comments: newest first

ShadowRam
Aug 12, 2008

Rank: not rated yet
OCZ NIA,

http://www.ocztec...actuator

The headband uses carbon nanofiber-based sensors to provide the highest possible dynamic range for the recording of bioelectrical signals that are amplified and digitized and further de-convoluted into computer commands.

Already uses this?
superhuman
Aug 12, 2008

Rank: 2.5 / 5 (2)
Nanotubes were shown to enter and damage cells so I wouldn't want them in my brain.

RayWilson
Aug 12, 2008

Rank: 5 / 5 (1)
I'm afraid Bush is too far gone for this to be of any use to him.
bredmond
Aug 12, 2008

Rank: not rated yet
Would it be useful for electrodes on the outside? not just implanted in the inside? If so, maybe it is still good enough to make a hat that I can wear to effectively control my computer.
E_L_Earnhardt
Aug 12, 2008

Rank: not rated yet
Try this on a cancer cell! Voltage applied will be about four electron volts positive!
Rank 4.3 /5 (23 votes)
Relevant PhysicsForums posts
  • Protease cleavage
    created3 hours ago
  • Pertubance in a model
    created9 hours ago
  • Cancer drugs and Alzheimer's, Oh my!
    created17 hours ago
  • Squishing cells
    created18 hours ago
  • Any books/articles for evolutionary stable strategy models in humans?
    createdFeb 09, 2012
  • Science behind the bore feeling?
    createdFeb 09, 2012
  • More from Physics Forums - Biology

More news stories

'Dark plasmons' transmit energy

Microscopic channels of gold nanoparticles have the ability to transmit electromagnetic energy that starts as light and propagates via "dark plasmons," according to researchers at Rice University.

Nanotechnology / Nanophysics

created 23 hours ago | popularity 5 / 5 (6) | comments 1 | with audio podcast

What lies beneath: Mapping hidden nanostructures

The ability to diagnose and predict the properties of materials is vital, particularly in the expanding field of nanotechnology. Electron and atom-probe microscopy can categorize atoms in thin sheets of material, ...

Nanotechnology / Nanophysics

created 7 hours ago | popularity 5 / 5 (1) | comments 1

New kind of solar cell could capture significantly more energy than current cells

New solar cells could increase the maximum efficiency of solar panels by over 25%, according to scientists from the University of Cambridge.

Nanotechnology / Nanophysics

created Feb 08, 2012 | popularity 4.5 / 5 (12) | comments 14 | with audio podcast

Nanoshell whispering galleries improve thin solar panels

Visitors to Statuary Hall in the U.S. Capitol Building may have experienced a curious acoustic feature that allows a person to whisper softly at one side of the cavernous, half-domed room and for another on ...

Nanotechnology / Nanomaterials

created Feb 07, 2012 | popularity 4.3 / 5 (6) | comments 6 | with audio podcast

Nanotube therapy takes aim at breast cancer stem cells

Wake Forest Baptist Medical Center researchers have again proven that injecting multiwalled carbon nanotubes (MWCNTs) into tumors and heating them with a quick, 30-second laser treatment can kill them.

Nanotechnology / Bio & Medicine

created Feb 09, 2012 | popularity 5 / 5 (1) | comments 0 | with audio podcast


CIA website offline, Anonymous takes credit

The website of the Central Intelligence Agency was unresponsive on Friday after the hacker group Anonymous claimed to have knocked it offline.

Q&A: Obama and the birth control controversy

(AP) -- What birth control debate? A half-century after the introduction of the pill, acceptance of birth control by American women is virtually universal.

Complex wiring of the nervous system may rely on a just a handful of genes and proteins

Researchers at the Salk Institute have discovered a startling feature of early brain development that helps to explain how complex neuron wiring patterns are programmed using just a handful of critical genes. ...

The power of estrogen -- male snakes attract other males

A new study has shown that boosting the estrogen levels of male garter snakes causes them to secrete the same pheromones that females use to attract suitors, and turned the males into just about the sexiest ...

New error-correcting codes guarantee the fastest possible rate of data transmission

Error-correcting codes are one of the triumphs of the digital age. They’re a way of encoding information so that it can be transmitted across a communication channel — such as an optical fiber o ...

Humans may have helped the decline of African rainforests 3000 years ago

(PhysOrg.com) -- Large areas of rainforests in Central Africa mysteriously disappeared over three thousand years ago, to be replaced by savannas. The prevailing theory has been that the cause was a change ...