Soft memory device opens door to new biocompatible electronics (w/ Video)

July 14, 2011
Conventional electronics are typically made of rigid, brittle materials and don't function well in a wet environment. "Our memory device is soft and pliable, and functions extremely well in wet environments -- similar to the human brain," says researcher Michael Dickey. Credit: Michael Dickey, North Carolina State University

Researchers from North Carolina State University have developed a memory device that is soft and functions well in wet environments – opening the door to a new generation of biocompatible electronic devices.

"We've created a memory device with the physical properties of Jell-O," says Dr. Michael Dickey, an assistant professor of chemical and biomolecular engineering at NC State and co-author of a paper describing the research.

Conventional electronics are typically made of rigid, brittle materials and don't function well in a wet environment. "Our memory device is soft and pliable, and functions extremely well in wet environments – similar to the human brain," Dickey says.

Researchers have created a memory device with the physical properties of Jell-O, and that functions well in wet environments. Credit: Michael Dickey, North Carolina State University

Prototypes of the device have not yet been optimized to hold significant amounts of memory, but work well in environments that would be hostile to traditional electronics. The devices are made using a liquid alloy of gallium and indium metals set into water-based gels, similar to gels used in biological research.

The device's ability to function in wet environments, and the biocompatibility of the gels, mean that this technology holds promise for interfacing electronics with biological systems – such as cells, enzymes or tissue. "These properties may be used for biological sensors or for medical monitoring," Dickey says.

This video is not supported by your browser at this time.
The individual components of the "mushy" memory device have two states: one that conducts electricity and one that does not. These two states can be used to represent the 1s and 0s used in binary language. Most conventional electronics use electrons to create these 1s and 0s in computer chips. The mushy memory device uses charged molecules called ions to do the same thing. Credit: Michael Dickey, North Carolina State University

The device functions much like so-called "memristors," which are vaunted as a possible next-generation memory technology. The individual components of the "mushy" memory device have two states: one that conducts electricity and one that does not. These two states can be used to represent the 1s and 0s used in binary language. Most conventional electronics use electrons to create these 1s and 0s in computer chips. The mushy uses charged molecules called ions to do the same thing.

In each of the memory device's circuits, the metal alloy is the circuit's electrode and sits on either side of a conductive piece of gel. When the alloy electrode is exposed to a positive charge it creates an oxidized skin that makes it resistive to electricity. We'll call that the 0. When the electrode is exposed to a negative charge, the oxidized skin disappears, and it becomes conducive to electricity. We'll call that the 1.

Normally, whenever a negative charge is applied to one side of the electrode, the positive charge would move to the other side and create another oxidized skin – meaning the electrode would always be resistive. To solve that problem, the researchers "doped" one side of the gel slab with a polymer that prevents the formation of a stable oxidized skin. That way one is always conducive – giving the device the 1s and 0s it needs for electronic memory.

Explore further: IMEC presents novel non-volatile memory capable of storing 9 bits per cell

Related Stories

Shape shifters: Researchers create new breed of antennas

December 1, 2009

(PhysOrg.com) -- Antennas aren't just for listening to the radio anymore. They're used in everything from cell phones to GPS devices. Research from North Carolina State University is revolutionizing the field of antenna design ...

New device may revolutionize computer memory

January 20, 2011

(PhysOrg.com) -- Researchers from North Carolina State University have developed a new device that represents a significant advance for computer memory, making large-scale "server farms" more energy efficient and allowing ...

Recommended for you

Reshaping the solar spectrum to turn light to electricity

July 28, 2015

When it comes to installing solar cells, labor cost and the cost of the land to house them constitute the bulk of the expense. The solar cells—made often of silicon or cadmium telluride—rarely cost more than 20 percent ...

Meet the high-performance single-molecule diode

July 29, 2015

A team of researchers from Berkeley Lab and Columbia University has passed a major milestone in molecular electronics with the creation of the world's highest-performance single-molecule diode. Working at Berkeley Lab's Molecular ...

1 comment

Adjust slider to filter visible comments by rank

Display comments: newest first

akaryrye
not rated yet Jul 15, 2011
so ... um ... what about the density of this memory?

Please sign in to add a comment. Registration is free, and takes less than a minute. Read more

Click here to reset your password.
Sign in to get notified via email when new comments are made.