- Stanford researchers demonstrated layers of materials having a thickness of just a few atoms stacked like paper sheets on top of the hot spots provide equivalent insulation to that of a 100 times thicker glass sheet.
- Researchers used a graphene layer and three other materials having a thickness of three atoms for creating an insulator of four layers which has a thickness of 10 atoms.
- The heat shield is very effective as on passing through each layer, atomic heat vibrations due to electrons-atom collisions are dampened, thereby losing energy.
These days smartphones, laptops come with a ton of features. Companies are making them more attractive with powerful enhancements both in design and technology. These come with a cost. In this case, devices get heated up quickly which if not controlled can lead to malfunctions and even explosion of devices.
To protect against these issues, scientists insert objects such as glass, plastic or even air layers for the purpose of insulation so that the components which generate heat such as microprocessors are prevented from damage and therefore make the use of the devices comfortable.
Researchers from the Stanford University have demonstrated that layers of materials having a thickness of just a few atoms which are stacked like paper sheets on top of the hot spots can provide equivalent insulation to that of a glass sheet that is 100 times thicker. In the near future, comparatively thinner heat shields will help in making electronic devices even more compact. The paper has been published in the journal Science Advances. Eric Pop, an electrical engineering professor said that now heat generated in electronic devices are being treated in a completely different fashion.
The heat generated from laptops or smartphones is in fact an inaudible form of sound having a high frequency. Electricity flows as the stream of electrons move through wires. In their motion, they collide with the atoms of the medium in which they are moving. With every collision, atoms of the medium vibrate and as the collisions increase the vibrations in the material generate energy which is felt as heat.
Viewing heat as a form of sound inspired scientists to draw upon principles of the physical world. Pop from his earlier stint as a radio DJ knew that recording studios are quiet due to the thick glass windows which block any external sound. This also applies to the present electronic devices. To make electronic devices thinner researchers borrowed the trick of homeowners who installed windows with air gaps between glass sheets with varying thickness to make homes quiet and warm. Sam Vaziri, lead author said that they similarly made an insulator which used several layers of material with a thickness of an atom instead of a thick glass sheet.
The atomically thin materials were only discovered 15 years ago. The first material was graphene comprising of one layer of carbon atoms. After that, researchers experimented with other materials that resembled a sheet. Researchers from Stanford used a graphene layer and three other materials having a thickness of three atoms for creating an insulator of four layers which has a thickness of 10 atoms. It is effective as on passing through each layer, atomic heat vibrations are weakened thereby losing energy.
For making these heat shields practical, scientists will have to find some technique by which they are easily produced. In the future, researchers wish to control vibrational energy inside materials similar to light and electricity. A new field of phononics is rising for understanding heat in solids as a type of sound.
Journal Ref: Ultrahigh thermal isolation across heterogeneously layered two-dimensional materials