2D stack provides thermal isolation in electronics

Stanford University created an atomically thin heat shield by stacking layers of two-dimensional materials, including graphene. Using Raman thermometry, they found atomic heat vibrations lose energy as they pass through each layer of the heat shield.

Lead author Sam Vaziri said: "We adapted that idea by creating an insulator that used several layers of atomically thin materials instead of a thick mass of glass.”

The research team said atomically thin heat shields provide the same insulation as a sheet of glass that is 100 times thicker. They can also be up to 50,000 times thinner than current insulators in phones and laptops, making future electronic devices not only cooler, but smaller.

Stanford University team used a single layer of graphene, as well as three layers each of molybdenum diselenide, molybdenum disulphide and tungsten diselenide, to create a four-layered insulator, 10 atoms deep.

Stanford said a mass production technique for such a heat shield could come in the form of a spray, which could also have applications in thermal energy harvesting or for routing heat in compact geometries.

Currently, glass, plastic or layers of air are used as insulation for heat-generating components such as microprocessors. Excess heat and insulation defects can cause lithium batteries – such as Samsung’s 3,500mAh battery in their Galaxy Note 7 – to combust.

Heat generated from electronic devices such as smartphones and laptops is actually an inaudible form of high-frequency sound. Stanford’s thermal metamaterials are an example of work in the still-emerging field of phononics.

Eric Pop, Professor of Electrical Engineering at Stanford, said: "We know quite a lot about how to control electricity, and we're getting better with light, but we're just starting to understand how to manipulate the high-frequency sound that manifests itself as heat at the atomic scale.”

The team’s research paper was published in Science Advances.