Thermoelectric Clathrate Material and the Kondo Effect Turns Industrial Waste Heat into Electricity

Clathrates: Tiny cages enclosing single atoms are shown.
Credit: TU Vienna

Researchers at the Vienna University of Technology (TU Vienna) have developed a material that can turn waste heat generated by machines into electricity using the Kondo effect and clathrates.

Researchers have designed a material that traps cesium atoms inside a lattice structure (clathrate). When the material is exposed to heat, the trapped atoms start vibrating within its lattice 'cage' and electricity is generated. This is due to the Kondo effect.

Named after Jun Kondo, a theoretical physicist from Japan, the Kondo effect describes how the electrical resistance of a metal increases when the temperature is lowered up to a certain point, known as the Kondo temperature.

The current research shows that the Kondo effect can also apply to very high temperatures.

What this means is that applications can be developed that will take advantage of waste heat produced by machines that can turn it into useful electrical energy rather than it being dissipated into the environment.

Heat Dissipation at the Atomic Level Studied Through Nanotechnology

Researchers at the University of Michigan are studying the effects of heat at the nanoscale; between atoms. This study will help in understanding how heat behaves in nanoscale systems.

Moore's Law states that the number of transistors on integrated circuits doubles approximately every two years. This equates to computing processing power doubling every two years. For the last 50 years, the trend in computers and electronics adheres to Moore's law but technological evolution is fast approaching to the limit of transistors that can fit into a single silicon chip.

At last count, the current record for most number of transistors put on a chip is 2 billion.

With circuit boards getting smaller and smaller, one factor that scientists and engineers look at is heat. As devices get smaller and smaller, the laws of thermodynamics particularly in heat transfer and heat dissipation gets complicated.

The UM researchers are looking at measuring this process at the nanoscale which is the behavior of heat between individual atoms. This study can help develop devices that are smaller, energy efficient, and faster than those currently available. This is a major hurdle for Moore's Law since technology is now going towards atomic scale nano-electronics.

Because of this, the International Technology Roadmap for Semiconductors in 2010 adjusted the law and changed the period from every two years to every three years.

MIT News: Manipulating Heat Using Lenses and Mirrors

Thermal lattices, shown here, are one possible application of the newly developed thermocrystals. In these structures, where precisely spaced air gaps (dark circles) control the flow of heat, thermal energy can be "pinned" in place by defects introduced into the structure (colored areas).
Illustration courtesy of Martin MaldovanCredit: MIT

Nanostructured semiconductor alloy crystals were engineered to manipulate heat, either through reflecting or focusing it.

Nanotechnology is the science behind the manipulation of atomic and molecular objects. These materials measure from 1 to 100 nanometers (nm). One nanometer is equal to one billionth, or 10⁻⁹ meters.

Nanostructures are one of the products from this technology. Nanostructures are engineered as a component for a bigger device. Nanostructures give support, assist in the process, or brings out a particular property from the created device.

There are three dimensions to a nanostructure:

• Nanotextured surfaces have one dimension on the nanoscale - only the thickness of the surface of an object is between 0.1 and 100 nm (a dot).
• Nanotubes have two dimensions on the nanoscale - the diameter of the tube is between 0.1 and 100 nm; its length could be much greater.
• Spherical nanoparticles have three dimensions on the nanoscale - the particle is between 0.1 and 100 nm in each spatial dimension (Length, Width, Height).

MIT News: Increasing Heat Coefficients on Industrial Plant Condensers Through Nanotechnology

Students at the Device Research Lab (DRL) in MIT’s mechanical engineering department have designed and tested a coated surface of an industrial plant condenser with nanostructured patterns that greatly increase the heat-transfer coefficient.

The heat-transfer coefficient is important when it comes to condensers because it is a measure of how fast heat can be transferred away from it. Basically, it is the opposite of insulation where insulation is a measure of how long heat can be maintained.

The purpose of a condenser in an industrial plant, like a thermal power plant for example, is to condense water vapor back into steam for maximum efficiency and reuse the now transformed liquid water in the steam generator or boiler as boiler feed water. A condenser with a high heat-transfer coefficient would then be able to condense water vapor faster and more efficiently.

Nanostructures and its uses

Nanotechnology, specifically nanostructures, have been proven successful in creating materials or devices that perform in a particular way, usually increasing its efficiency in the process. Nanostructures are objects created at the nanoscale or atmolecular level. These are very tiny structures and creating a nanostructure involves manipulating an object's composition at a molecular level. It may involve moving molecules or atoms around, or creating patterns that will allow it to behave in a particular way.

These structures are made to either act as a container in a delivery system (like gas atom/molecule in a very tiny capsule), interact with other objects to achieve a predetermined outcome either structurally or chemically or to act as a base for a more complex structure.

In relation to the condenser created by MIT, the surface was coated with nanostructured patterns to influence the way water droplets behave on it (see embedded video below).

Using Thermoacoustics To Develop Self-Powered Nuclear Reactor Backup Sensors

A thermoacoustic device uses sound waves to move heat from one place to another or use heat to create sound waves. Using this principle, a thermoacoustic engine uses either the heat transfer or the sound waves to produce electricity, cooling, or heat pumping.


Currently, researchers are looking into electricity created from pressure (piezoelectricity), refrigeration, and cryogenic applications.


Another category thermoacoustics can be of use, is in the development of sensors, particularly backup sensors for nuclear reactors. The Fukushima nuclear disaster is a prime example of this.


In the Fukushima incident, the power connections failed cutting off electricity to the backups, pumps, and sensor systems shutting them down. The reactors overheated due to the high radioactive decay heat and the nuclear plant's operators could not monitor the fuel rods in the reactor and spent fuel in the storage ponds.

Dung Beetles Use Dung As A Mobile Thermal Refuge For Thermoregulation

Dung beetles are also called scarab beetles. These are the same beetles worshiped by the ancient Egyptians. They believed that a giant dung beetle rolled the Sun across the sky and buried it at night.

They probably got the idea from observing that these beetles roll balls of manure across the plain and bury it under the ground. Dung beetles do this since they use these balls of dung for food or as a brooding ball where the female beetle will lay its eggs inside it. When the larvae hatches, they feed on the dung.

There are some dung beetles that feed on mushrooms, leaves, and fruits. Dung beetles that solely rely on dung as its food source, do not need to drink or eat anything else since all the nutrients are provided for by the dung.

American Chemical Society Briefing: Eating cool: What to Eat To Beat The Heat

The refreshing chill of today's fudge-brownie cookie-crumble ice cream cone ― will it really last? Or can ice cream actually stoke the body's metabolic furnace and make you feel even hotter? How about a few ice-cold brews? Or should you add a dash of the counter-intuitive to your summer menu with the sweat-inducing, mouth-on-fire, tear-provoking taste of chili peppers?

With millions of people already weather-worn after a summer punctuated by record heat, and some of the hottest days still ahead, the American Chemical Society (ACS) today is hosting a special briefing, "Eating Cool: What to Eat to Beat the Heat." It is part of the 244th National Meeting & Exposition of the ACS, which is the world's largest scientific society. The meeting, featuring 8,600 presentations on new discoveries in science and other topics, continues here through Thursday and is expected to attract 14,000 scientists and others.

"Eating Cool: What to Eat to Beat the Heat" will begin at noon today in the ACS Press Center, Room 304, in the Pennsylvania Convention Center for journalists covering the meeting onsite. The press conference room is fully equipped for TV coverage and video. Those covering the event from their home space can join the briefing online. The video can be seen below on 21 Aug 2012, 12:00 ET (21-Aug-2012 16:00 GMT).