Project of Excellence „BlueMat“: Revolution through Water

Exzellenzprojekt BlueMat Grafik
© TU Hamburg/Martin Künsting

Materials that change color like a chameleon or smart windows that only allow certain rays of sunlight to pass through - this could become reality through the targeted use of water in the "BlueMat: Water-Driven Materials" project at Hamburg University of Technology. The Cluster of Excellence, with which the university is now applying for funding for the first time as part of the German government's Excellence Strategy, aims to conduct research into materials that are inspired by nature and develop completely new properties through interaction or contact with water.

The preliminary work for this comes from the Collaborative Research Center SFB 986 "Tailor-made Multi-Scale Material Systems" (duration 2012-2024). Research into materials inspired by nature has already been carried out here too, explains "BlueMat" spokesperson and Professor of Materials and X-ray Physics Patrick Huber: "Over the last 30 years, we as researchers have increasingly understood how nature manages to use relatively simple elements to produce highly robust substances and materials that fulfill many functions." One example: teeth. "These achieve an unimagined hardness," says Huber. Artificially producing materials like a tooth was the task of the Collaborative Research Center (SFB).

Smart windows could regulate temperatures in buildings

"This preliminary work has positioned the TU Hamburg very well for our current "BlueMat" project," says Huber. The innovation in the excellence project? "We design the materials so that they react to water." For example, artificially grown silicon crystals. The surface of the material appears colored because it reflects incident light in a certain way, like a mirror - in red, for example. Such processes can also be found in nature: Chameleons, in whose skin cells there are tiny types of crystals, control their color in a similar way. By introducing water, the color of the cultured silicon can be changed to blue, for example. One advantage of this technique is that the ability to color materials using water would make the use of color pigments, which can contain unhealthy substances, unnecessary.

In the field of architecture, water-driven materials can be used for smart windows, for example, which control the heat balance in buildings. To achieve this, water would be integrated into the surface of the window. When sunlight hits this water in the window and it evaporates, only certain rays would be filtered and allowed through, depending on their intensity in the early morning or late afternoon, in summer or winter. In the long term, this could reduce the use of air conditioning systems because the temperature is regulated by the smart windows.

© TU Hamburg
Color change in the silicon

"We are working on the next industrial revolution"

Glass displays could also be built with water on the surface, as is the case with smart windows. It would be possible to "write" on these displays using an infrared laser: when water is vaporized by the laser, the writing on the display becomes visible at these points.

Last but not least, the TU Cluster of Excellence's research could be used in the field of hydrovoltaics. Similar to the principle of photovoltaics, which produces energy with the help of sunlight, water is used here. When a structure becomes wet and then dries again, as happens at high and low tide, the evaporation of the water molecules generates energy that could be used to charge batteries, for example. "The big advantage of this," explains Huber, "is that if there is no sunlight, photovoltaics won't work. If there is no wind, you can't use wind energy. But there will always be high and low tides, so hydrovoltaics can be used at all times."

The TU scientist began researching the topic of water 15 years ago and is still fascinated by the element: "Water played a major role in the first industrial revolution back in the 18th century, when it was used in machines such as steam locomotives. Now we are working on the next industrial revolution, so to speak, in which water is used in materials."

University cooperation

For the potential Cluster of Excellence, the TU is joining forces with several Hamburg partner institutions in working groups. Materials are produced and applied at the TU Hamburg. At the Deutsches Elektronen-Synchrotron (DESY), these materials are analyzed using X-ray methods to see, for example, how water moves through thin cavities (capillaries) in the material. The Max Planck Institute and Helmut Schmidt University are working on the shape and composition, i.e. modeling. The water-based materials are also to be used in modern art installations via the University of Fine Arts.


More information

Please find more information on the project's website.