Featured Research

from universities, journals, and other organizations

Gem of an idea: A flexible diamond-studded electrode implanted for life

Date:
October 6, 2010
Source:
Case Western Reserve University
Summary:
Researchers are building implants made of diamond and flexible polymer that are designed to identify chemical and electrical changes in the brain of patients suffering from neural disease, or to stimulate nerves and restore movement in the paralyzed. The implant would last for life and, capable of both stimulating and monitoring nerves, save space.

Diamonds adorning tiaras to anklets are treasures, but these gemstones inside the body may prove priceless.

Two Case Western Reserve University researchers are building implants made of diamond and flexible polymer that are designed to identify chemical and electrical changes in the brain of patients suffering from neural disease, or to stimulate nerves and restore movement in the paralyzed.

The work of Heidi Martin, a professor of chemical engineering, and Christian Zorman, a professor of electrical engineering and computer science, is years from human trials but their early success has drawn interest worldwide.

"Right now, we're trying to develop diamond-coated electrodes for implantable devices which last a lifetime," Martin said. "A patient would have one surgery and that's it."

For most materials, it's hell inside the body. But even inside us, a diamond is forever. Unlike standard electrodes, diamonds won't corrode, Martin said.

Diamond is so hard and rigid, however, that an entire implant made of the stuff would quickly damage surrounding tissue and the body would seal off the implant as if it were a splinter, Zorman said.

The key is to use just enough diamond. " We only need diamond at the biological interface -- where the device connects with a nerve," Zorman said.

To marry one of the world's hardest materials and a flexible plastic, Martin and Zorman use much the same process used to manufacture computer chips.

Martin's lab grows diamond film -- real diamond -- under high temperature, in a vacuum. By adding impurities they change the diamond's properties. For electrodes, the team adds boron, turning the diamond blue. Blue diamonds, including the famous Hope Diamond at the Smithsonian, conduct electricity.

Because diamond is made at 800 to 900 degrees Celsius, a temperature that would melt the polymer base, Martin first selectively grows a series of tiny squares of diamond film on silicon dioxide, the stuff of sand and quartz.

Zorman's group then lays down a thin flexible polymer that fills in the gaps between diamonds, followed by a layer of metal that connects to the back of the diamonds and will conduct electricity. Lastly, he adds a thick layer of flexible polymer base. They then dip the device in hydrofluoric acid, which eats away the silicon dioxide and frees the probe.

Small, cortical probes that measure chemical changes at a location in the brain or along a nerve have two diamond contacts affixed. These probes are designed to assist health researchers who are trying to understand the role of chemicals in stimulating nerves or communicating within the brain.

Recent research has found, for example, a link between a deficiency in the neurotransmitter dopamine and Parkinson's disease.

Currently, medical researchers are using carbon-based needle electrodes to monitor neurotransmitters. But, the electrode is fragile -- a glass tube supports the carbon, Martin said. The polymer and diamond probe can remain in the body much longer and the diamond has proved exceptional at chemical sensing, Martin said.

Martin and Zorman also build electrodes with arrays of eight or more electrically-connected diamond segments. These are designed for neruoprostheses, to stimulate nerves, enabling a paralyzed patient to stand or a blind patient to see.

With space inside the body at a premium, the diamond has another advantage. Lab tests show one diamond-coated electrode can monitor chemical and electrical signals as well as stimulate nerves.

Martin has also found another way to make a flexible probe coated with diamond, by growing diamond film on a wire of rhenium alloy. Metals typically become brittle in the high-heat of diamond processing.

But she's able to bend a diamond-coated tungsten-rhenium wire 75 degrees before fracturing and a molybdenum-rhenium alloy more than 90 degrees.

Martin, Zorman and their lab staff have been invited to several leading international conferences this year to talk about the work, including the Electrochemical Society meeting in Vancouver in April and the European Materials Research Society meeting, Strasbourg, France in June. They also presented this work at the 2010 Solid State Sensor, Actuator and Microsystems Workshop in Hilton Head SC in June.

Martin spoke at Budapest, Diamond 2010: 21st European Conference on Diamond, Diamond-Like Materials, Carbon Nanotubes, and Nitrides, last month and will talk at a Veterans' Affairs seminar in Cleveland in December.

"The potential to help make a device that can help clinically and advance research would be so thrilling," Martin said. "The time scale is long, but I think we have a good chance at it."


Story Source:

The above story is based on materials provided by Case Western Reserve University. Note: Materials may be edited for content and length.


Cite This Page:

Case Western Reserve University. "Gem of an idea: A flexible diamond-studded electrode implanted for life." ScienceDaily. ScienceDaily, 6 October 2010. <www.sciencedaily.com/releases/2010/10/101005121824.htm>.
Case Western Reserve University. (2010, October 6). Gem of an idea: A flexible diamond-studded electrode implanted for life. ScienceDaily. Retrieved September 18, 2014 from www.sciencedaily.com/releases/2010/10/101005121824.htm
Case Western Reserve University. "Gem of an idea: A flexible diamond-studded electrode implanted for life." ScienceDaily. www.sciencedaily.com/releases/2010/10/101005121824.htm (accessed September 18, 2014).

Share This



More Matter & Energy News

Thursday, September 18, 2014

Featured Research

from universities, journals, and other organizations


Featured Videos

from AP, Reuters, AFP, and other news services

Virtual Reality Headsets Unveiled at Tokyo Game Show

Virtual Reality Headsets Unveiled at Tokyo Game Show

AFP (Sep. 18, 2014) Several companies unveiled virtual reality headsets at the Tokyo Game Show, Asia's largest digital entertainment exhibition. Duration: 00:48 Video provided by AFP
Powered by NewsLook.com
Stocks Hit All-Time High as Fed Holds Steady

Stocks Hit All-Time High as Fed Holds Steady

AP (Sep. 17, 2014) The Federal Reserve signaled Wednesday that it plans to keep a key interest rate at a record low because a broad range of U.S. economic measures remain subpar. Stocks hit an all-time high on the news. (Sept. 17) Video provided by AP
Powered by NewsLook.com
Space Race Pits Bezos Vs Musk

Space Race Pits Bezos Vs Musk

Reuters - Business Video Online (Sep. 16, 2014) Amazon CEO Jeff Bezos' startup will team up with Boeing and Lockheed to develop rocket engines as Elon Musk races to have his rockets certified. Fred Katayama reports. Video provided by Reuters
Powered by NewsLook.com
MIT's Robot Cheetah Unleashed — Can Now Run, Jump Freely

MIT's Robot Cheetah Unleashed — Can Now Run, Jump Freely

Newsy (Sep. 16, 2014) MIT developed a robot modeled after a cheetah. It can run up to speeds of 10 mph, though researchers estimate it will eventually reach 30 mph. Video provided by Newsy
Powered by NewsLook.com

Search ScienceDaily

Number of stories in archives: 140,361

Find with keyword(s):
Enter a keyword or phrase to search ScienceDaily for related topics and research stories.

Save/Print:
Share:

Breaking News:
from the past week

In Other News

... from NewsDaily.com

Science News

Health News

Environment News

Technology News



Save/Print:
Share:

Free Subscriptions


Get the latest science news with ScienceDaily's free email newsletters, updated daily and weekly. Or view hourly updated newsfeeds in your RSS reader:

Get Social & Mobile


Keep up to date with the latest news from ScienceDaily via social networks and mobile apps:

Have Feedback?


Tell us what you think of ScienceDaily -- we welcome both positive and negative comments. Have any problems using the site? Questions?
Mobile: iPhone Android Web
Follow: Facebook Twitter Google+
Subscribe: RSS Feeds Email Newsletters
Latest Headlines Health & Medicine Mind & Brain Space & Time Matter & Energy Computers & Math Plants & Animals Earth & Climate Fossils & Ruins