Texas A&M engineers map how charge moves through materials for brain-like computers

A Texas A&M University chemical engineering team has used computer simulations to explain how electric charge travels through a class of porous materials that researchers hope to use in computers modeled on the brain.

The study, published in the Journal of the American Chemical Society, was led by professor Perla Balbuena with postdoctoral researcher Alejandro Aviles Sanchez, the university's College of Engineering reported on Oct. 2.

What they studied

The materials are metal-organic frameworks, or MOFs: tiny three-dimensional lattices in which metal centers are joined by organic molecules called linkers. Some of them conduct electricity, but scientists have not fully worked out how charge travels through them.

The team modeled a zinc-based framework whose conductivity shifts as electrons are added. In the simulations, electrons did not flow freely through the whole structure. They jumped from one particular site on the linkers to the next, and ions sitting nearby, such as potassium, affected that motion.

"The most important result is that ions inside the material can make it easier for electrons to move," Aviles said. "This shows that the movement of ions and electrons is closely connected."

Why engineers care

Ordinary digital computers keep memory and processing in separate places, so data shuttles back and forth and burns energy, Balbuena said. The brain stores and processes information in the same place, which has pushed researchers toward analog and neuromorphic designs built from materials whose electrical behavior shifts in response to a stimulus.

The university described the work as fundamental research. The researchers said the mechanism they found could inform how other redox-active frameworks, and materials that act like them, are designed.

Balbuena's group works with experimental scientists in the Texas A&M Department of Chemistry, at Sandia National Labs and at the National Laboratory of the Rockies. The project falls under ReMIND, an Energy Frontier Research Center supported by the U.S. Department of Energy and led by Texas A&M. The paper is titled "Ion-Electron Coupling-Driven Redox Behavior in Metal-Organic Frameworks."

Sources

stories.tamu.edu

pubs.acs.org