Graphene thermal conductivity - introduction and latest news - Page 19

Thermene launched the second-generation Thermene product, which is a graphene-based high-performance thermal paste. Thermene is used to cool processor and video cards. The second generation product offers better performance (up to 12° Celsius cooler than the first generation) and is also cheaper by 25%.

The company says that the graphene-based paste handily beats the performance of Arctic Silver 5 and other standard thermal pastes by an average of 7° Celsius. The $14.99 product comes in a 3 mL syringe which improves the application experience, and one syringe of Thermene can be applied on up to 15 standard-size processors. The 2nd-gen Thermene is now shipping worldwide.

Researchers from the University of California, Riverside and the University of Manchester discovered that coating copper with graphene (on both sides) strongly enhances the heat conducting properties of the copper.

The researchers say that coating the copper with one-layer graphene sheets increased heat conducting properties up to 24%. They say that this method could be used to built better hybrid copper graphene interconnects for electronic chips. The researchers explain that the improvement is the result of changes in copper’s nano- and microstructure, not from graphene's action as an additional heat conducting channel.

Angstron Materials (owned by Nanotek Instruments and based in Ohio, USA) is a graphene nanoplatelets (GNPs) and single-layer graphene sheets developer and producer.

Ian Fuller, the company's marketing and business development chief, was kind enough to answer a few questions we had regarding the company's technology and business. Ian joined Nanotek Instruments in 2006, focusing on fuel cells. He later joined the Angstron Materials team.

Researchers from Purdue university suggest a new way to control the flow of heat in electronic devices. The idea is to use triangular structures to control phonons (a quantum-mechanical phenomena that describe how vibrations travel through a material's crystal structure). Small triangular graphene flakes is one possible such structure.

The researchers used simulations to show that those triangular (and also other T-shaped structures) are capable of "thermal rectification," or permitting a greater flow of heat in one direction than in the opposite direction. Rectification has made possible transistors, diodes and memory circuits central to the semiconductor industry. The new devices are thermal rectifiers that might perform the same function, but with phonons instead of electrical current.

Researchers at Purdue University are developing a new graphene "nanopetals" mass production process. Those nanopetals are graphene-based vertical nanostructures that look like tiny rose petals, and they have applications in sensors, heat-management, supercapacitors and batteries. This research is funded with a $1.5 million grant from the NSF.

The researchers hope to increase the production speed of nanopetal-coated surfaces to 10 square meters per hour, using a roll-to-roll process. This is a dramatic increase to current "laboratory-scale" production rate. The new process will use a vacuum-based plasma-enhanced chemical vapor deposition (PECVD).

Thermene launched a new product based on graphene - the Thermene Graphene Thermal Paste is based on graphene-oxide flakes and is aimed towards CPU cooling. The company just started selling this new product a few days ago. For $20 you can buy 3 ml of Thermene which should be enough for about a dozen CPUs.

Thermene is easy to use - it comes with a simple paint brush and you simply apply it to your CPU surface. The material takes 10 hours to cure.

Covetics is a new hybrid made from high-strength carbon and metal, and it is the first bonded nanocarbon-metal material with significantly enhanced properties that can survive repeated melting cycles. Silver-based covetics were found to respond to physical and mechanical loadings in a superior way than polymers or metals. Covetics can improve thermal and electrical conductivity and yield strength and resist corrosion and oxidation.

A company called Third Millennium Materials (or TM²) was established in the US to commercialize this new material, invented by the company's founders. The company was awarded five patents to date, including one in early 2013 for the metal-carbon composition and the invention of silver covetic. The company filed 15 patents for 15 different Covetics metal elements.

The National Science Foundation (NSF) awarded a $360,000 three-year grant to three professors from the University of California, Riverside (UCR) to further study th thermal properties of graphene. The future goal of this study is to find new heat-removal approaches for electronic and optoelectronic devices.

This specific project will investigate the effect of rotation angle on the thermal conductivity of twisted bilayer graphene. The UCR team will study the possibility of suppressing the phonon coupling in twisted graphene layers, allowing for the transfer of extraordinary large heat fluxes. The phonons are quanta of crystal lattice vibrations that carry heat in graphene.

Researchers from Chalmers University of Technology in Sweden have demonstrated how graphene can dissipate heat in silicon based electronics. The researchers placed a graphene sheet on an electronic device hot-spots - which reduced the working temperature by 25%.

All electronic devices generate heat. The devices (processors, for example) include those hot-spots where the work is most intensive. These spots are small (on a micro or nano scale). In their experiment, the hotspots had a normal temperature of 55 to 115 degrees Celsius. The graphene layer reduced it by up to 13 degrees.

American Graphite Technologies (AGT) announced that Cheap Tubes received independent test results for its hybrid bucky/graphene paper formulations and advanced coating technology, and these results confirmed that the materials are conductive, stable and processable on an industrial scale.

Cheap Tubes produced several pre-production quality, highly conductive, flexible and mechanically stable self-supporting membrane samples (made form CNTs and GNPs), refined from mined graphite and other nano components. Cheap Tubes' hybrid paper has a surface area of 116m²/g at 100um thickness, and the company says that it could potentially produce it in sizes up to 36" wide, at speeds up to 50-100 feet of membrane per minute.