Forum für Wissenschaft, Industrie und Wirtschaft

Hauptsponsoren:     3M 


A Quantum Dot Energy Harvester: Turning Waste Heat into Electricity on the Nanoscale

A new type of nanoscale engine has been proposed that would use quantum dots to generate electricity from waste heat, potentially making microcircuits more efficient.

"The system is really a simple one, which exploits certain properties of quantum dots to harvest heat," Professor Andrew Jordan of the University of Rochester said. "Despite this simplicity, the power it could generate is still larger than any other nanoengine that has been considered until now."

An array on nano energy harvesters in what the researchers call a "swiss cheese" arrangement.

The engines would be microscopic in size, and have no moving parts. Each would only produce a tiny amount of power – a millionth or less of what a light bulb uses. But by combining millions of the engines in a layered structure, Jordan says a device that was a square inch in area could produce about a watt of power for every one degree difference in temperature. Enough of them could make a notable difference in the energy consumption of a computer.

A paper describing the new work is being published in Physical Review B by Jordan, a theoretical physics professor, and his collaborators, Björn Sothmann and Markus Buttiker from the University of Geneva, and Rafael Sánchez from the Material Sciences Institute in Madrid.

Jordan explained that each of the proposed nanoengines is based on two adjacent quantum dots, with current flowing through one and then the other. Quantum dots are manufactured systems that due to their small size act as quantum mechanical objects, or artificial atoms.

The path the electrons have to take across both quantum dots can be adjusted to have an uphill slope. To make it up this (electrical) hill, electrons need energy. They take the energy from the middle of the region, which is kept hot, and use this energy to come out the other side, higher up the hill. This removes heat from where it is being generated and converts it into electrical power with a high efficiency.

To do this, the system makes use of a quantum mechanical effect called resonant tunneling, which means the quantum dots act as perfect energy filters. When the system is in the resonant tunneling mode, electrons can only pass through the quantum dots when they have a specific energy that can be adjusted. All other electrons that do not have this energy are blocked.

Quantum dots can be grown in a self-assembling way out of semiconductor materials. This allows for a practical way to produce many of these tiny engines as part of a larger array, and in multiple layers, which the authors refer to as the Swiss Cheese Sandwich configuration (see image).

How much electrical power is produced depends on the temperature difference across the energy harvester – the higher the temperature difference, the higher the power that will be generated. This requires good insulation between the hot and cold regions, Jordan says.

Contact: Leonor Sierra
About the University of Rochester
The University of Rochester ( is one of the nation's leading private universities. Located in Rochester, N.Y., the University gives students exceptional opportunities for interdisciplinary study and close collaboration with faculty through its unique cluster-based curriculum. Its College, School of Arts and Sciences, and Hajim School of Engineering and Applied Sciences are complemented by its Eastman School of Music, Simon School of Business, Warner School of Education, Laboratory for Laser Energetics, School of Medicine and Dentistry, School of Nursing, Eastman Institute for Oral Health, and the Memorial Art Gallery.

Leonor Sierra | EurekAlert!
Further information:

More articles from Physics and Astronomy:

nachricht Gamma ray camera offers new view on ultra-high energy electrons in plasma
28.10.2016 | American Physical Society

nachricht Scientists measure how ions bombard fusion device walls
28.10.2016 | American Physical Society

All articles from Physics and Astronomy >>>

The most recent press releases about innovation >>>

Die letzten 5 Focus-News des innovations-reports im Überblick:

Im Focus: Neuartige Lichtquellen aus zweidimensionalen Materialien

Physiker der Universität Würzburg haben eine Lichtquelle hergestellt, die Doppelpacks von Photonen emittiert. Zwei-Photonen-Quellen eignen sich besonders gut, um Informationen abhörsicher zu verschlüsseln. Wesentliche Zutaten des Experiments waren ein Halbleiter-Kristall – und etwas Tesafilm.

Im Zentrum der Arbeit stehen so genannte Monolagen. Um diese „Super-Materialien“ (so das renommierte Wissenschafts-Magazin „Nature“) ist in den vergangenen...

Im Focus: Novel light sources made of 2D materials

Physicists from the University of Würzburg have designed a light source that emits photon pairs. Two-photon sources are particularly well suited for tap-proof data encryption. The experiment's key ingredients: a semiconductor crystal and some sticky tape.

So-called monolayers are at the heart of the research activities. These "super materials" (as the prestigious science magazine "Nature" puts it) have been...

Im Focus: Medica 2016: Neuer Kunststoff der TU Kaiserslautern macht medizinische Steckverbindungen sicherer

Kanülen, Spritzen oder Katheter – ein Großteil medizintechnischer Produkte besteht aus Kunststoff. Auch beim sogenannten Luer-System, einer Steckverbindung für Medizin-Schläuche, ist dies der Fall. Aufgrund von Spannungen kann es hier mit der Zeit zu Rissen kommen, wodurch etwa Luft in eine Infusionslösung geraten kann. Die Folge kann eine Embolie sein. Ingenieure der TU Kaiserslautern haben ein Luer-System mit einem neuen langlebigeren Kunststoff entwickelt. Risse breiten sich deutlich später aus. Auf der Medizintechnikmesse Medica in Düsseldorf stellen die Forscher ihre Arbeit vom 14. bis 17. November am Gemeinschaftsstand Rheinland-Pfalz (Halle 7a, Stand B06) vor.

Bei Infusionen kommt das sogenannte Luer-System zum Einsatz. Es verbindet zum Beispiel verschiedene Spritzen, Schläuche sowie Kanülen – etwa mit...

Im Focus: Mikrostrukturen mit dem Laser ätzen

Mit dem Ultrakurzpulslaser lassen sich nicht nur feine Strukturen schneiden, in einem Verbundprojekt haben Wissenschaftler untersucht, wie man damit auch Mikrostrukturen in Dünnglas erzeugen kann. Anwendungen gibt es im Analytikbereich (lab-on-a-chip), aber auch in der Elektronikbranche und im Consumer-Bereich gibt es großes Interesse.

Am Anfang dieser neuen Methode stand ein überraschender Effekt: Wenn Glas mit dem Ultrakurzpulslaser in der richtigen Weise bestrahlt wird, wird es so...

Im Focus: Etching Microstructures with Lasers

Ultrafast lasers have introduced new possibilities in engraving ultrafine structures, and scientists are now also investigating how to use them to etch microstructures into thin glass. There are possible applications in analytics (lab on a chip) and especially in electronics and the consumer sector, where great interest has been shown.

This new method was born of a surprising phenomenon: irradiating glass in a particular way with an ultrafast laser has the effect of making the glass up to a...

Alle Focus-News des Innovations-reports >>>



im innovations-report
in Kooperation mit academics

Copycat: Natur als Blaupause für Innovation?

28.10.2016 | Veranstaltungen

Heilbronner Verkehrsgespräche zum Thema Logistikinnovationen am 7. November 2016

28.10.2016 | Veranstaltungen

Instandhaltung der Bauwerke an den Wasserstraßen

28.10.2016 | Veranstaltungen

Weitere VideoLinks >>>
Aktuelle Beiträge

Wenn Fettzellen die Farbe ändern

28.10.2016 | Biowissenschaften Chemie

MHH-Forscher reparieren geschädigte Blutgefäße mit Nanopartikel-Therapie

28.10.2016 | Medizin Gesundheit

Sand- oder Marmorkuchen? - Neue Einblicke zum Plattenrecycling der Erde

28.10.2016 | Geowissenschaften