A fundamental law of material science could be rewritten by graphene: in simulations and experiment, scientists have shown that graphene’s heart absorption varies with the size of the sample, which means it could absorb an unlimited amount of heat.
Up until now, French physicist Joseph Fourier’s observations have held true: namely, that conductivity is an intrinsic material property, that’s independent of size or shape. But researchers from the Max Planck Institute for Polymer Research (MPI-P) in Mainz and the National University of Singapore have shown that might not be the case for graphene. Davide Donadio, one of the researchers, explains to R&D:
“We recognised mechanisms of heat transfer that actually contradict Fourier’s law in the micrometer scale. Now all the previous experimental measurements of the thermal conductivity of graphene need to be reinterpreted. The very concept of thermal conductivity as an intrinsic property does not hold for graphene, at least for patches as large as several micrometers.”
Indeed, through computer simulation and real-life experiment, the team found that the thermal conductivity of graphene increases logarithmically with the size of the sample. That means that, as you use larger samples, more heat can be absorbed per unit length. It’s a material science first, and one that changes the way scientists think about the heat absorption of materials.
Why care? Well, the finding could be massive news for micro- and nano-electronics, where heat rejection is a massive limiting factor. Introducing materials with theoretically unlimited thermal absorption would be an amazing advance alone; remember that graphene conducts, and you’re essentially looking at the possibility of developing self-cooling circuitry. In other words: this could be an electronics engineer wet dream. [Nature Communications via R&D]
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