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Brains Improved by Graphene Are on the Horizon

Researchers gain better understanding of how graphene interacts with brain cells to increase neuron activity

2 min read
Single-layer graphene (SLG) increases neuronal firing by altering membrane-associated functions in cultured cells.
Image: SISSA

While graphene has been tapped to deliver on everything from electronics to optoelectronics, it’s a bit harder to picture how it may offer a key tool for addressing neurological damage and disorders. But that’s exactly what researchers have been looking at lately because of the wonder material’s conductivity and transparency.

In the most recent development, a team from Europe has offered a deeper understanding of how graphene can be combined with neurological tissue and, in so doing, may have not only given us an additional tool for neurological medicine but also provided a tool for gaining insights into other biological processes.

In research described in the journal Nature Nanotechnology, a group from the International School for Advanced Studies (SISSA), in Trieste, Italy, and the Catalan Institute of Nanoscience and Nanotechnology (ICN2) in Spain have demonstrated that single-layer graphene increases neuronal firing by altering membrane-associated functions in cultured cells.

“The results demonstrate that, depending on how the interface with [single-layer graphene] is engineered, the material may tune neuronal activities by altering the ion mobility, in particular potassium, at the cell/substrate interface,” said Laura Ballerini, a researcher in neurons and nanomaterials at SISSA.

Ballerini provided some context for this most recent development by explaining that graphene-based nanomaterials have come to represent potential tools in neurology and neurosurgery.

“These materials are increasingly engineered as components of a variety of applications such as biosensors, interfaces, or drug-delivery platforms,” said Ballerini. “In particular, in neural electrodes or interfaces, a precise requirement is the stable device/neuronal electrical coupling, which requires governing the interactions between the electrode surface and the cell membrane.”

This neuro-electrode hybrid is at the core of numerous studies, she explained, and graphene, thanks to its electrical properties, transparency, and flexibility, represents an ideal material candidate.

“Our work provides important insights on the deep interactions of technology with nature.”

In all of this work, the real challenge has been to investigate the ability of a single atomic layer to tune neuronal excitability and to demonstrate unequivocally that graphene selectively modifies membrane-associated neuronal functions.

The researchers hypothesized that there would be specific interactions between graphene and potassium ions in the extracellular solution, crucially regulating cell excitability. By experimental and theoretical approaches, they further hypothesized that crucial to these effects are the graphene-specific cation-pi interactions, which are noncovalent molecular interactions between a cation—an ion with fewer electrons than protons, giving it a positive charge—and an electron-rich system (the pi). These cation-pi interactions are maximized by the single-layer graphene, according to Ballerini, which in turn impacts cell excitability.

“Our work provides important insights on the deep interactions of technology with nature,” said Ballerini. “Novel and outstanding materials might then represent, in general, unconventional and exciting tools to gain insights into genuine biological processes. In turn, biological processes may hint at describing unconventional properties, new physics, and applications of the materials.”

Ballerini notes that for this line of research, the group will ultimately have to move to in vivo conditions, which poses different challenges both in engineering devices to be tested in real life and in analyzing biological outcome. However, for now Ballerini and her colleagues will focus on the design of a smart device that takes advantage of their expertise in biology and nanomaterials.

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3 Ways 3D Chip Tech Is Upending Computing

AMD, Graphcore, and Intel show why the industry’s leading edge is going vertical

8 min read
Vertical
A stack of 3 images.  One of a chip, another is a group of chips and a single grey chip.
Intel; Graphcore; AMD
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A crop of high-performance processors is showing that the new direction for continuing Moore’s Law is all about up. Each generation of processor needs to perform better than the last, and, at its most basic, that means integrating more logic onto the silicon. But there are two problems: One is that our ability to shrink transistors and the logic and memory blocks they make up is slowing down. The other is that chips have reached their size limits. Photolithography tools can pattern only an area of about 850 square millimeters, which is about the size of a top-of-the-line Nvidia GPU.

For a few years now, developers of systems-on-chips have begun to break up their ever-larger designs into smaller chiplets and link them together inside the same package to effectively increase the silicon area, among other advantages. In CPUs, these links have mostly been so-called 2.5D, where the chiplets are set beside each other and connected using short, dense interconnects. Momentum for this type of integration will likely only grow now that most of the major manufacturers have agreed on a 2.5D chiplet-to-chiplet communications standard.

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