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Insulator 4 Layers Heat Shield

Scientists manufacture 10 atoms thick heat shield to protect electronic devices

  • 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

Natural ways to avoid the heat

Natural ways to avoid the heat

Cranking up the air conditioner isn’t the only way to deal with the stifling heat that is blanketing much of North America and Europe.

Washington State University architect Omar Al-Hassawi is an expert at reducing indoor temperatures without the use of electricity.

His research blends ancient architectural practices with modern innovations to produce surprising results.

Whether you lack an air conditioner or are trying to cut your utility bill, Al-Hassawi can help. Here are a few of his suggestions for beating the heat this summer.

Ventilation strategies

In a climate like the Inland Northwest where temperatures drop by 30-35 degrees Fahrenheit at night, natural ventilation is an effective alternative to blasting the air conditioning.

Opening home windows after sunset and leaving them open until about 10 a.m. the next morning will help flush out the heat generated indoors the day before, Al-Hassawi said.

Conversely, closing windows during the hottest time of the day, from around noon till about an hour before sunset, will minimize heat gain.

Proper shading techniques

Another useful strategy for keeping home temperatures cool is shading exterior windows from the outside instead of the inside with blinds, curtains or even foliage.

“This acts like a hat for the windows similar to how we use hats to shade and protect ourselves,” Al-Hassawi said. “Exterior shading for windows facing south and west is especially effective.”

Home occupants can also wear very light clothing and avoid high heat-generating activities such as intense exercising and cooking meals during the afternoon. A cold shower or placing some cool water in front of a low flow fan are also good ways to create evaporative cooling and reduce indoor temperatures.

No stranger to the heat

Headshot of Omar Al-Hassawi
Omar Al-Hassawi

Al-Hassawi grew up in Iraq where temperatures rarely dip below 110 degrees Fahrenheit in summertime. For hundreds of years, people in the region incorporated downdraft and evaporative cooling techniques into their architectural designs that harnessed the power of wind and water to keep inside temperatures bearable.

Tall, hollow towers were often placed at the corners of homes to direct breezes down and let warm air escape. Often times, a pool of water would be placed at the base of the towers. As the air flowed over the water, it would evaporate and the air would absorb moisture, becoming cooler before passing into the home. Al-Hassawi said interest in adopting these passive cooling techniques in places like the United States has been on the rise in recent years as annual summer temperatures continue to increase across the country.

“Humans have been using architectural designs and other natural techniques to keep their homes cool for a very long time,” Al-Hassawi said. “We are starting to see a rebirth of a lot of these techniques which is a great thing considering the large role the building sector plays in global warming.”

One idea is to modify the wind tower concept by placing the evaporative cooling mechanism at the top of the tower instead of at its base. As warm air passes into the top of the tower, it would cool down because of the increase in moisture from the water. Then, the cool air would become heavier and drop naturally into the building by gravity.

“The tests I’ve done show that incorporating this type of cooling system into modern homes, particularly in a place like the Pacific Northwest, could bring temperatures down by as much as 30 degrees,” Al-Hassawi said. “So, if it is 100 F outside you can get 70 F inside.”

Materials provided by Washington State University

Krafla geothermal power station

Researchers develop technique to exploit geothermal energy in a sustainable manner

The way we fuel our power production has been significantly changed by the demand to limit emissions and ascent of renewables, from wind to solar to biomass. Those technologies are the world’s most appealing, energizing and emerging technologies which aim at producing energy. However, there is a massive, permanent and unused energy resource which is existing literally under our noses. We are referring to geothermal energy. Generation of geothermal energy is possible through the devices to make use of heat inside the Earth’s crust.

Researchers from Tokyo Tech have made major progress in understanding and advancement of sensitized thermal cells (STCs) which is a type of battery that can produce electric power at 100-degree Celsius or less. The study has been published in the Journal of Materials Chemistry A.

Before this, they have proposed the use of STCs as a new method for converting heat directly into electric power using dye-sensitized solar cells. They likewise replaced the dye with a semiconductor to enable the system to work using heat rather than light.

In the new cell, an electron transport layer (ETM), a semiconductor layer (germanium), and a solid electrolyte layer (copper ions) are sandwiched between the electrodes of the battery where electrons get thermally excited while going from a low-energy state to a high-energy state in the semiconductor and finally shifting naturally to the ETM.

Oxidation and reduction reaction involving copper ions take place at the interconnection of both electrolytes while electrons travel from the electrode through an external circuit, pass through the counter electrode, and then reach the electrolyte. This completes an electric circuit shifting low-energy electrons to the semiconductor layer. Scientists during the experiment found out that after a certain time, the electricity stopped flowing instead of working as a perpetual machine. This is due to the completion of redox reactions at the electrolyte end owing to the shifting of different types of copper ions.

Existence of heat simply opens up the external circuit for a short time reverting the situation. Dr Sachiko Matsushita, study leader said that heat which is considered as low-grade energy, would become a great renewable energy source with such design. Scientists are excited about the model as it is nature-friendly and has the possibility to solve the global energy crisis.

Moreover, he added that there is no fear of costly oil, radiation or instability of power generation when done with the help of sun or wind. The goal of future research will be the enhancement of battery with the belief of solving mankind energy needs without harming the earth.

Journal Reference: Journal of Materials Chemistry A

Researchers show the test device for assessing the heat-moving capabilities of the cooling wood.

Researchers develop sustainable wood with improved cooling capacities

It would have been awesome if instead of using expensive devices, the building material of the house performed the cooling and reduced the electricity expenses. Scientists from the University of Maryland and Colorado have used the technology found in nature for solving the heat problems which is also sustainable. The results of this study have been published in the Science journal.

Researchers have found the solution in wood which is sustainable and is already used for building homes. By using the structures found in wood, the cellulose nanofibres and the chambers which allow the passage of water and nutrients, the optical properties of the wood expel the heat.

Professor Jian Li of Northeast Forestry University remarked that due to this research, wood can be used in fighting the current energy crisis. University of Maryland professor, Liangbing Hu along with the co-authors of the paper Tian Li and Shuaiming He has been working on the advanced applications of wood for several years now. The team has invented many wide-ranging technologies based on wood such as transparent wood, affordable batteries based on wood and also a water purifier.

The cooling wood is only composed of wood and it does not contain any other component like polymer. When it will be used for building purposes, this material can cool down the building without the help of external sources such as water, electricity.

Lignin is removed from the wood, which is the component responsible for the strength and brown colour of the wood. By removing it, researchers manufactured a pale wood comprising of cellulose nanofibres. For making it water repellent, a hydrophobic component was added for protecting the wood. This led to a white building material suitable for making the roof of buildings to repel heat.

For testing purposes, the wood was taken to the farms in Arizona which has sunny weather. The cooling wood was tested and they found that on average it remained five to six degrees Fahrenheit cooler than the normal temperature. Even in the hottest time of the day, the wood remained cooler than air. When compared to the normal wood in sunlight, it remains 12 degrees cooler.

On the strength aspect, the per weight mechanical strength of the wood is more than steel which is why it is very suitable for construction purposes. As compared to natural wood it is 10 times stronger and also passes the scratch test.

Researchers found that in hotter cities like Phoenix, Honolulu this cooling wood would save the maximum energy and in the buildings made after 2004, it would save 20% of the cooling costs.

solar panels array

Scientists develop new material for improving efficiency of solar panels

Clean energy acts as an intersection which acts as a suitable substitution for fossil fuels. It is noticed that solar power plants have to boost their planning in a better way to compete with the electrical output of the non-renewable energy sources. The design highly depends upon the renovation and growth of newly made products such that they ingest and interchange the heat at the higher temperatures.

 The solar panels which are found on the hybrid cars or the residential rooftops are found lesser compared to the ones found in the solar power plants. Since the solar panels found in the power plants are huge and countless in number so the heat they absorb is more so they absorb more thermal energy from the sun as much as they can and then they create a passage so that the heat can pass through and that heat is converted into fluid-filled converter is known as heat exchanger.

A liquid version of carbon dioxide which is known as supercritical CO2 acts as an agency in converting the energy and the hotter the fluid gets the more the electricity can be produced. Researchers from the University of Toledo have discovered a newer technology based on the supercritical CO2 as a channel which helps in converting into energy and here this fluid minimizes the manufacturing costs and also minimizes the electricity level and commits to working in a good manner with accuracy and it can benefit to the future power plants too. This report was published in Nature journal

An assistant professor in the mechanical engineering department at Texas A&M University Dorrin Jarrahbashi said that the metal material which is used to make the solar panel heat exchangers using supercritical CO2 energy cycles are only firm up to 550 degrees Celsius and he also added that if the heat rises then break down occurs which leads to the replacement of the components and becomes less effective.

To solve this problem the researchers developed a new complex material which had a combination of ceramic and tungsten which is refractory metal which can take the heat of over 750 degrees Celsius. The tendency to tolerate heat can lead to more effectiveness in generating electricity in united solar and supercritical CO2 power plants by 20%. Compared to the fossil fuels the output and the longevity of the mixture and the lower cost in production will help in cutting down the price of construction and maintenance of powerplants.

It is said that with the help of the unique chemical, mechanical and thermal properties there is numerous approach for the compound. It started from improving its nuclear power plants to building rocket nozzles the results of this revolution has made a vast impact in the future of research and industry.