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Graphene Composites Go Big

First fabrication of composites containing large sheets of graphene outperforms all others in conductivity and strength

1 min read
Graphene Composites Go Big
Photos: Oak Ridge National Laboratory

Graphene is a wonder material — flexible, transparent, light, strong, and electrically and thermally conductive, qualities that have led to research worldwide into weaving these atom-thick layers of carbon into advanced devices. Now scientists have demonstrated what they say is the first large-scale fabrication of a graphene composite—a material that combines graphene with another substance to form something with new properties.

Until now, labs could only incorporate tiny flakes of graphene or graphene-like materials into composites. The mechanical and electrical capabilities of these composites were never as good as scientists would have liked because of weak links between the flakes, and the flakes often clumped together, leading to irregularities across the composites.

Now scientists at Oak Ridge National Laboratory and their colleagues have fabricated composites made up of plastic and 5-centimeter-by-5-cm sheets of graphene. This advance builds on previous work of theirs synthesizing graphene via chemical vapor deposition, which involves growing sheets of the material directly from hydrocarbon vapor on metal catalysts such as copper.

Using large flat or rolled-up graphene sheets avoids the previous problem of flake clumping. All in all, these new composites outperform state-of-the-art graphene composites in terms of both mechanical properties and electrical conductivity while using 50 times less graphene, potentially helping make this material competitive in the market, the researchers say.

Future research could explore reducing the cost and demonstrating the scalability of these composites. The scientists detailed their findings online 28 April in the journal Applied Materials & Interfaces.

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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
A stack of 3 images.  One of a chip, another is a group of chips and a single grey chip.
Intel; Graphcore; AMD

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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