Smartphones and laptops start to heat when in use which can often be discomforting to users. Excess heat is also known to lead to malfunctions and even cause lithium batteries to explode. Often times glass, plastic, and layers of insulation are used to prevent heat-generating components of electronic devices from causing damage. Now, researchers at Stanford University have illustrated that a few layers of atoms can provide the same quality of insulation as 100 thick sheets of glass—these studies may someday provide the basis for engineering more compact electronics than what we have today.
"We're looking at the heat in electronic devices in an entirely new way," says Eric Pop, professor of electrical engineering and senior author of the study which was published in Science Advances.
Believe it or not, the heat felt from cellular usage or working on your laptop is actually an inaudible form of high-frequency sound. This is because the flowing electricity allows a stream of electrons to collide with the atoms causing a vibration. The continuous vibration generates energy that is felt as heat.
It is long known that studios for music are quiet from the construction of thick glass windows that block exterior sound—this principle inspired the study in generating better shielding on electronic devices. "We adapted that idea by creating an insulator that used several layers of atomically thin materials instead of a thick mass of glass," stated postdoctoral scholar Sam Vaziri, the lead author on the paper.
Stanford University: This greatly magnified image shows four layers of atomically thin materials that form a heat-shield just two to three nanometers thick, or roughly 50,000 times thinner than a sheet of paper. (Image credit: National Institute of Standards and Technology)
Specifically, researchers used a layer of graphene along with three other sheet-like materials to create a four-layered insulator that is just 10 atoms deep. The idea of developing atomically thin materials is a fairly a new concept. Roughly, 15 years ago scientists for the first time isolated some materials into such thin layers—one such example is graphene which is a single layer of carbon atoms that has inspired new applications in recent years.
The developed insulator is effective enough because the atomic heat vibrations are dampened and thus lose most of the energy as they pass through every layer. "As engineers, 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," Pop said.
Source: Science Daily
