These fluidic windows are meant to sustainably improve the energy footprint of buildings. Large-surface capillary structures are integrated into their glass, which circulate a liquid suitable for the respective application. In the latest prototype of the EU-funded project LaWin (Large Area Fluidic Windows) led by Dr. Lothar Wondraczek from the Otto-Schott Institute of Materials Research at the University of Jena, the liquid is being enriched with small magnetic iron particles that can be drawn out with a magnet or in by turning the magnet off. Depending on the amount of iron particles, the liquid takes on a different shade of gray or turns completely black. Any incoming sunlight is thus absorbed accordingly, heating up the liquid.

The attainable heat production per area can be compared with that of standard solar-thermal systems. In this way, large area fluidic windows can replace air conditioners, shading systems and water heating in a single unit. The latest research report ("A Large-Area Smart Window with Tunable Shading and Solar-Thermal Harvesting Ability Based on Remote Switching of a Magneto-Active Liquid") was published in Advanced Sustainable Systems 1 (2018) and is available online free-of-charge as an open access document under a CC license.