Research advances brain-inspired computing materials

Among them, metal-organic frameworks (MOFs) are a class of materials with promising potential for advanced electronics.

In a recently published paper in the Journal of the American Chemical Society, Texas A&M University chemical engineering professor Dr. Perla Balbuena and postdoctoral researcher Dr. Alejandro Aviles Sanchez examined the fundamental mechanisms that govern electron and ion transport in these materials.

“This analysis is possible because of advanced computer simulations that allow us to see how individual parts of these materials interact and move, helping us understand how those small-scale behaviors affect the material as a whole,” Balbuena said.

While the work is fundamental in nature, the findings could help guide the development of future electronics capable of adapting their behavior, including emerging technologies such as neuromorphic devices for the next generation of analog computers.

“Our goal was to understand how electrons move through the MOF and how changes in its structure and nearby ions affect that movement,” Aviles said. “The most important result is that ions inside the material can make it easier for electrons to move. This shows that the movement of ions and electrons is closely connected.”

MOFs are tiny three-dimensional networks made of metal centers connected by organic molecules, known as linkers. Their unique structures give them a range of chemical and electronic properties. While some MOFs can conduct electricity, scientists do not yet fully understand how charge moves through these materials.

In the MOF study used in the research, conductivity changes as electrons are added. Balbuena’s team wanted to understand the microscopic mechanism behind this behavior and how the movement of electrons is influenced by the surrounding ions and structure.

The team examined a zinc-based MOF containing organic linkers. Through simulations, they found that electrons move through the material by “hopping” between specific sites on the linkers, rather than moving freely throughout the entire structure.

The findings can help researchers better understand the potential of MOFs for neuromorphic computing, an approach inspired by how the brain processes and stores information.

“In conventional digital computers, processing and memory are physically separated, so data must constantly move between them, which consumes significant energy,” Balbuena said. “In contrast, biological brains are extremely energy efficient, having memory and computing located in one region. This has inspired analog and neuromorphic approaches that aim to reproduce some of that efficiency using materials whose electrical behavior can change in response to stimuli, like neurons do.”

Materials that can change their electrical behavior in response to external stimuli could eventually play a role in analog and neuromorphic technologies designed to process information more efficiently.

“Together with experiments, this gives us a clearer picture of how the material works,” Aviles said. “The mechanism we identified may also help explain and guide the design of other redox-active MOFs, and other materials that may behave like them.”

Balbuena’s team interacts with experimental scientists based at Sandia National Laboratories, the National Renewable Energy Laboratory, and the Texas A&M Department of Chemistry. The work is part of Reconfigurable Electronic Materials Inspire by Nonlinear Neuron Dynamics (ReMIND), a Department of Energy-supported Energy Frontier Research Center led by Texas A&M.