SoylentNews

upstart writes:

Submitted via IRC for ErnestTBass

Study shows the potential of carbon nanotubes to cool electronic circuits

The use of solid-state refrigerators to cool appliances and electronic devices is a possible technological application for a theoretical study conducted at the University of Campinas (UNICAMP) in São Paulo State, Brazil.

Although this application is not considered in the study, which was based on computer simulations, such applications are on the horizon and could be an efficient and environmentally friendly alternative to vapor-compression refrigerators, which currently dominate the market and contribute to ozone depletion and global warming.

The study, led by Alexandre Fonseca with participation by his former student Tiago Cantuário, was part of the project "Carbon nanostructures: modeling and simulations," supported by São Paulo Research Foundation—FAPESP. The results are published in an article in the journal Annalen der Physik.

"Solid-state cooling is a young field of research with promising results. The method we investigated is based on the so-called elastocaloric effect (ECE), which makes use of temperature variations in a system in response to mechanical stress. We performed computer simulations of this effect in carbon nanotubes," Fonseca said.

[...] "We began our research on the basis of an article entitled 'Elastocaloric effect in carbon nanotubes and graphene', published in 2016 by Sergey Lisenkov and collaborators. It described a computer simulation study showing that when a small deformation was applied to carbon nanotubes, corresponding to up to 3% of their initial length, they responded with a temperature variation of up to 30 °C," Fonseca said.

"In contrast with Lisenkov's research, which simulated only simple strain and compressive force applied to the nanotubes, we reproduced the process computationally for a complete thermodynamic cycle. In our simulation, we considered two phases—nanotube strain and release—and two heat exchanges with two external reservoirs. We estimated the heat that would be extracted by the nanotube if it was in ideal contact with a certain medium. We obtained a good result for the performance coefficient compared with those of other experimentally tested materials."

[...] "The core problem in electronics is cooling. Our motivation was imagining a device that could use a simple cycle to extract heat from an appliance. Carbon nanotubes proved highly promising," he said. "They also have another virtue, which is that they're small enough to be embedded in a polymer matrix, a desirable property at a time when manufacturers are investing in research and development to obtain flexible electronic devices such as foldable smartphones." All this is part of a larger picture in which vapor-compression refrigerators are replaced by solid-state refrigerators in the context of global climate change.

Original Submission