Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Variable glass coatings to stop condensation on windows

07.10.2014

Thin-film coatings impart new properties to glass in applications as diverse as window glazing, solar cells and touchscreens. With the Megatron® sputtering system, it is now possible for the first time to vary the materials in these coatings in any way and to produce entirely new coatings with improved surface quality. The researchers will be presenting the Megatron® at the glasstec trade fair in Düsseldorf from October 21 to 24 (Hall 15, Booth A33).

When it’s frosty outside and cozy and warm indoors, a little bit of heat always escapes through the windows. Triple glazing is intended to keep as much of the expensive heating energy inside the house as possible, but this solution also has its downside, which is most noticeable at nightfall and in the early hours of the morning.


The Megatron® enables the scientists at Fraunhofer IST to create new combinations of materials.

© Fraunhofer IST/Jan Benz


Simulated plasma discharge in a cutaway model of the Megatron®.

© Fraunhofer IST

The drop in outside temperature causes the outermost pane to cool down significantly overnight, and moisture in the air is deposited as condensation. The result is misty windows. A conductive coating on the outer pane could stop condensation by preventing the small quantity of heat that penetrates the outer pane from being radiated to the cold outdoor environment.

This coating must also be scratchproof to withstand the weathering effects of wind and weather. Indium tin oxide, a material used to coat touchscreens, offers these properties. But its one major disadvantage is cost: indium is very rare and therefore expensive. If triple-glazed windows were to be coated with this material, their already high price would climb even higher.

Megatron® offers fast route to the optimum coating

The Megatron® sputtering system, developed in-house by researchers at the Fraunhofer Institute for Surface Engineering and Thin Films IST in Braunschweig, opens the way to the development of entirely new coating systems – for applications of all kinds. In the case of triple glazing, the researchers have opted for a solution based on titanium oxide.

“Titanium is much cheaper than indium, but it isn’t conductive,” says IST group leader Dr. Volker Sittinger. “So we dope the titanium with niobium.” In other words, the researchers deliberately contaminate the coating material in order to make it conductive. But how much niobium is needed to optimize the glass pane’s anti-misting properties? Until now there was no easy way to answer this question – until the Megatron® came along. “Unlike conventional sputtering systems, the Megatron® allows us to vary the doping concentration to any required level. It also enables us to increase the coating rate and obtain a smoother surface,” says Sittinger.

Conventional sputtering processes involve bombarding a solid object such as an ingot of titanium, referred to as the target, with energy-rich ions in a vacuum chamber. These ions knock a number of titanium atoms out of the target material, which are deposited on the glass substrate in the form of a very thin film. The doping process normally requires the presence of niobium ions in the target material, but this also implies that the concentration of this element is defined from the outset. The Megatron® system developed by IST researchers takes a different approach. “In this case we have two separate targets, one made of titanium and the other of niobium. This gives us total freedom to define the doping concentration. We can vary it in any way we choose, and even produce gradients, i.e. progressively increase or decrease the concentration of dopant within the thickness of the film,” explains Sittinger. This method can be used, for example, to enhance the efficiency of solar cells.

Coatings based on new combinations of materials

The Megatron® also allows entirely new coatings to be created by combining materials in a film that cannot be mixed in the form of a target, and were therefore impossible to produce up to now. For instance, a combination of tungsten and titanium dioxide could be used to create self-cleaning surfaces for interior spaces. When UV light hits a film of pure titanium dioxide, it breaks down any organic particles found there. If the titanium dioxide film is doped with tungsten, the organic dirt particles are broken down and detached when exposed to natural daylight.

Before building the Megatron®, the scientists carried out simulations to answer questions such as: What is the best way to separate the gas systems of the two vacuum chambers containing the different targets? What baffles are required, and where should they be positioned? The simulations enabled Sittinger and his colleagues to find the appropriate solutions, and the software developed by the IST team is already being used by the R&D departments of industrial plant manufacturers. The researchers will be presenting the Megatron® itself at the glasstec trade fair in Düsseldorf from October 21 to 24 (Hall 15, Booth A33).

Dr. Volker Sittinger | Fraunhofer-Institute

Further reports about: Titanium coating concentration condensation dioxide glass ions materials particles titanium dioxide

All articles from Trade Fair News >>>

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 >>>