Researchers at the University of Texas at Austin have developed a transistor that operates like synapses in the brain. Image: The University of Texas at Austin.
Researchers at the University of Texas at Austin have developed a transistor that operates like synapses in the brain. Image: The University of Texas at Austin.

Computers that think more like human brains are inching closer to mainstream adoption. But many unanswered questions remain. Among the most pressing is: what types of materials can serve as the best building blocks to unlock the potential of this new style of computing?

For most traditional computing devices, silicon remains the gold standard. However, there is a move to use more flexible, efficient and environmentally friendly materials for brain-like, neuromorphic devices.

Researchers from the University of Texas at Austin have now developed synaptic transistors for brain-like computers using the thin, flexible material graphene. These transistors are similar to the synapses in the brain that connect neurons to each other.

"Computers that think like brains can do so much more than today's devices," said Jean Anne Incorvia, an assistant professor in the Department of Electrical and Computer Engineering at the University of Texas at Austin, and lead author of a paper on this work in Nature Communications. "And by mimicking synapses, we can teach these devices to learn on the fly, without requiring huge training methods that take up so much power."

With new high-tech concepts like self-driving cars, drones and robots, we are reaching the limits of what silicon chips can efficiently do in terms of data processing and storage. For these next-generation technologies, a new computing paradigm is needed. Neuromorphic devices mimic processing capabilities of the brain, a powerful computer for immersive tasks.

“Biocompatibility, flexibility and softness of our artificial synapses is essential,” said Dmitry Kireev, a post-doctoral researcher at the University of Texas at Austin, who co-led the project. “In the future, we envision their direct integration with the human brain, paving the way for futuristic brain prosthesis.”

A combination of graphene and nafion, a polymer membrane material, make up the backbone of the novel synaptic transistor. Together, these materials demonstrate key synaptic-like behaviors – most importantly, the ability for the pathways between transistors to strengthen over time as they are used more often, a type of neural muscle memory. In computing, this means that devices will be able to get better at tasks like recognizing and interpreting images over time and do it faster.

Another important finding is that these transistors are biocompatible, which means they can interact with living cells and tissue. That is key for potential applications in medical devices that come into contact with the human body. Most materials used for early brain-like devices are toxic, so they would not be able to interact with living cells in any way.

Neuromorphic platforms are already starting to become more common. Leading chipmakers such as Intel and Samsung have either produced neuromorphic chips or are in the process of developing them. However, current chip materials place limitations on what neuromorphic devices can do, so academic researchers are working hard to find the perfect materials for soft brain-like computers.

"It's still a big open space when it comes to materials; it hasn't been narrowed down to the next big solution to try," Incorvia said. "And it might not be narrowed down to just one solution, with different materials making more sense for different applications."

This story is adapted from material from the University of Texas at Austin, with editorial changes made by Materials Today. The views expressed in this article do not necessarily represent those of Elsevier. Link to original source.