Whitney Palmer

NCSU researchers develop ‘Jell-O’-like memory implants

Published in the Oct. 3, 2011, Raleigh News & Observer and Charlotte Observer

By Whitney L.J. Howell

Electronic devices hold data just as the brain does, but until now that’s been the only characteristic these hard, inflexible machines shared with the organ that stores memories. Two N.C. State engineers, however, are turning these rigid mechanisms into bendable, water-loving circuits.

By combining water-based gels with liquid metal, researchers Michael Dickey and Orlin Velev build computer chip-like devices that thrive in wet environments, such as the body.

“We’re not trying to replace computer chips,” Velev said. “We’re turning soft matter into

Under development at N.C. State: Gloved fingers hold a flexible memristor - an information storage device "similar to Jell-O." Courtesy: North Carolina State University

electrical circuits. These are memristors – information storage devices – that are similar to Jell-O.”

Although the devices currently hold only a few bits of information, they could enhance medical monitoring equipment or biomedical research one day, Dickey said. They could be implanted in the human body without any function loss.

“Wet environments don’t adversely affect these memristors, making them a good match for biological work,” he said. “Plus, they’re soft and easily squished.”

To construct the devices, Dickey and Velev microwave a water-based gel and put it in an electrode-shaped mold to cool. By adding a layer of liquid metal – a mixture of gallium and indium – on either side of the conductive gel, much like the bread on a sandwich, they create an electricity-conducting pathway.

The metal alloy layers are gatekeepers for electrical charges. They form oxidized skins that control whether positive or negative signals reach the gel. The thicker the skin, the more resistant it is to the charge. Gallium influences the thickness of the oxidized layer, Dickey said, preventing it from completely blocking an electrical signal. The constant signal flow creates the electronic memory.

Although these devices hold great potential for improving cardiac or neural monitoring equipment, they’re too slow and too big to be truly useful now, said Chad Bossetti, biomedical engineering assistant professor at East Carolina University.

“The circuits need to move signals faster than every few seconds because the body transmits electric signals at about four times that rate,” Bossetti said. “Miniaturization is also important. The technology is currently scaled up for development, but they must make it smaller for it to make a significant impact.”

To read the story on the Raleigh News & Observer website: http://www.newsobserver.com/2011/10/03/1535611/more-to-think-about-jell-o-like.html 

To read the story on the Charlotte Observer website: http://www.charlotteobserver.com/2011/10/03/2659284/more-for-your-brain-to-think-about.html#storylink=misearch

October 3, 2011 - Posted by wjpalmer | Science | Chad Bossetti, electronic memory devices, electronic memory devices work in water, gallium, indium, information storage devices similar to Jell-O, information storage devices that work inside human body, memristors, Michael Dickey, N.C. State University engineering, Orlin Velev