Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Micro energy harvesters for the Internet of Things

11.10.2018

Fraunhofer IWS Dresden scientists print electronic layers with polymer ink

Thin organic layers provide machines and equipment with new functions. They enable, for example, tiny energy recuperators. In future, these will be installed on pipes or other surfaces in order to convert waste heat into electricity. The experts at the Fraunhofer Institute for Material and Beam Technology IWS Dresden use ink based on conductive polymers for this purpose.


The engineers coated a glass plate with a particularly smooth and conductive polymer layer of “Poly(Kx[Ni-itto])” by rotation coating (“spin coating”).

Fraunhofer IWS Dresden


Dr. Roman Tkachov examines a film printed with two different conductive polymers at a dispensing printer in the Fraunhofer IWS Dresden.

Fraunhofer IWS Dresden

The IWS engineers have developed a new process for this project: Small molecules are synthesized into polymers which are able to transport negative charge carriers (electrons). The “trick” is that this polymer, unlike comparable polymers, is in a liquid state. This polymer enables the scientists to print or spray very thin and smooth organic functional coatings on surfaces.

“We want to construct thermoelectric generators that, for example, supply energy to sensors in places that are difficult to access, where battery replacement is not useful, not possible or very expensive,” reports Lukas Stepien, who, together with Dr. Roman Tkachov, manages this development project at Fraunhofer IWS Dresden. Warm pipes that do not get hotter than 100 degrees Celsius - this is the upper limit for the polymers investigated so far.

“Additionally, this technology might also benefit the 'Internet of Things': sensors and other electronic components using thermoelectric generators could cover their own electrical energy requirements. An external power supply will be no longer necessary,” adds Lukas Stepien.

Thermoelectric generators suffer from low efficiency so far

“Thermoelectric generators” have been known as concept for years. However, their efficiency is still far too low for large-scale use: on average, they convert only six percent of the heat energy received into electricity. “The fact that this technology has not yet been able to establish itself might probably be also due to the industry's excessively high expectations,” reports Lukas Stepien. “Today's polymer-based thermoelectric generators, unfortunately, usually deliver only a few milliwatts.

If, however, we succeed in significantly increasing this efficiency, far-reaching consequences for the German energy balance might result: Car manufacturers, for example, have long been dreaming of coating their engines with such thermoelectric generators.

Manufactures strive for electrical recycling of the waste heat from the drive units, which had previously been painstakingly cooled away. The fuel consumption of cars could thus be reduced by up to a tenth, according to estimates. However, solutions so far tested are not very effective.

Fraunhofer polymers also tolerate air contact

With Fraunhofer IWS polymer technology things could change in the future. Roman Tkachov and Lukas Stepien have already taken an important step: they have found a way to liquefy polymers of the so-called “n-conductor type” (where “n” stands for negative charge carriers) in order to further process them.

An important point here is that these polymer layers remain comparatively stable even after use under everyday conditions. That is not self-evident. Such long organic molecules tend to age and lose their special properties when they come into contact with air.

Dr. Roman Tkachov and Lukas Stepien have developed a multi-stage process to produce their inks based on conductive polymers. They initially modify the short elements for polymers, the so-called monomers, chemically. Subsequently they are dissolved in a liquid. Once the polymers have joined, the liquid material can be processed by print, spray or other coating methods.

“In principle, these polymers have already been printable,” emphasizes Lukas Stepien. “But as long as they are in a solid state dispersion, that is, a particle mixture is necessary.” The dissolved polymers, on the other hand, allow very high-quality smooth layer structures, which – depending on the process – are only a tenth to ten micrometers (thousandths of a millimeter) thick.

Potential also for organic solar cells

This in turn allows for more compact and effective components than previously used polymers. “In perspective, we also see great potential for the construction of organic transistors and solar cells,” emphasizes Dr. Roman Tkachov. Until then, however, some research work still needs to be done.

Next, the engineers will initially concentrate on further increasing the electrical conductivity of their polymers. They also aim at producing the first prototypes of thermoelectric generators from their new materials. “And of course we will have to work on further increasing the efficiency of these generators,” says Dr. Roman Tkachov.

Wissenschaftliche Ansprechpartner:

Group Manager Printing
M.Sc. Lukas Stepien | Fraunhofer-Institut für Werkstoff- und Strahltechnik IWS | Phone +49 351 83391-3092 | Winterbergstraße 28 | 01277 Dresden | www.iws.fraunhofer.de | lukas.stepien@iws.fraunhofer.de

Weitere Informationen:

http://www.iws.fraunhofer.de/en/pressandmedia.html

Markus Forytta | Fraunhofer-Institut für Werkstoff- und Strahltechnik IWS

More articles from Power and Electrical Engineering:

nachricht How electric heating could save CO2 emissions
17.12.2018 | Technische Universität München

nachricht Data use draining your battery? Tiny device to speed up memory while also saving power
14.12.2018 | Purdue University

All articles from Power and Electrical Engineering >>>

The most recent press releases about innovation >>>

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

Im Focus: Data storage using individual molecules

Researchers from the University of Basel have reported a new method that allows the physical state of just a few atoms or molecules within a network to be controlled. It is based on the spontaneous self-organization of molecules into extensive networks with pores about one nanometer in size. In the journal ‘small’, the physicists reported on their investigations, which could be of particular importance for the development of new storage devices.

Around the world, researchers are attempting to shrink data storage devices to achieve as large a storage capacity in as small a space as possible. In almost...

Im Focus: Data use draining your battery? Tiny device to speed up memory while also saving power

The more objects we make "smart," from watches to entire buildings, the greater the need for these devices to store and retrieve massive amounts of data quickly without consuming too much power.

Millions of new memory cells could be part of a computer chip and provide that speed and energy savings, thanks to the discovery of a previously unobserved...

Im Focus: An energy-efficient way to stay warm: Sew high-tech heating patches to your clothes

Personal patches could reduce energy waste in buildings, Rutgers-led study says

What if, instead of turning up the thermostat, you could warm up with high-tech, flexible patches sewn into your clothes - while significantly reducing your...

Im Focus: Lethal combination: Drug cocktail turns off the juice to cancer cells

A widely used diabetes medication combined with an antihypertensive drug specifically inhibits tumor growth – this was discovered by researchers from the University of Basel’s Biozentrum two years ago. In a follow-up study, recently published in “Cell Reports”, the scientists report that this drug cocktail induces cancer cell death by switching off their energy supply.

The widely used anti-diabetes drug metformin not only reduces blood sugar but also has an anti-cancer effect. However, the metformin dose commonly used in the...

Im Focus: New Foldable Drone Flies through Narrow Holes in Rescue Missions

A research team from the University of Zurich has developed a new drone that can retract its propeller arms in flight and make itself small to fit through narrow gaps and holes. This is particularly useful when searching for victims of natural disasters.

Inspecting a damaged building after an earthquake or during a fire is exactly the kind of job that human rescuers would like drones to do for them. A flying...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

VideoLinks
Industry & Economy
Event News

ICTM Conference 2019: Digitization emerges as an engineering trend for turbomachinery construction

12.12.2018 | Event News

New Plastics Economy Investor Forum - Meeting Point for Innovations

10.12.2018 | Event News

EGU 2019 meeting: Media registration now open

06.12.2018 | Event News

 
Latest News

Pressure tuned magnetism paves the way for novel electronic devices

18.12.2018 | Materials Sciences

New type of low-energy nanolaser that shines in all directions

18.12.2018 | Physics and Astronomy

NASA research reveals Saturn is losing its rings at 'worst-case-scenario' rate

18.12.2018 | Physics and Astronomy

VideoLinks
Science & Research
Overview of more VideoLinks >>>