We've already seen the idea of harnessing the power of human motion to generate electricity used in many fields, including footwear, roads, and, just this week, an implantable stimulator device for treating injured tendons,media reported. One of these possibilities is a floor that can power electronic devices, and scientists at ETH Zurich have now developed an efficient form of this technology that is powerful enough to power LED light bulbs and small electronic devices.
In de loop der jaren hebben wetenschappers een aantal innovatieve vloeroplossingen onderzocht die elektriciteit kunnen opwekken door menselijke bewegingen, waaronder keramische tegels voor binnen- en buitengebruik, en sponsachtig hout dat afhankelijk is van het piëzo-elektrische effect om spanning op te wekken onder mechanische druk. Dit nieuwe voorbeeld vertoont enkele overeenkomsten met een ander voorbeeld dat we in 2016 zagen, waarin wetenschappers cellulose-nanovezels in houten vloeren insloten, waardoor een elektrische lading ontstond wanneer deze door het zogenaamde -tribo-elektrische effect werd getrild.
The triboelectric effect also forms the basis for the new smart wood floor, which consists of two treated wood veneers with electrodes layered underneath. But to get the performance to the desired level, some tinkering is required to address the limited power generation capacity of wood. "Wood is basically neutral," said Guido Panzarasa, senior author of the study. "This means that wood has no real tendency to gain or lose electrons. So the challenge is to make wood able to attract and lose electrons."
The team's solution involved coating one piece of wood with a silicone that readily gains electrons on contact, and embedding metal ions and organic molecules on another piece of wood, giving it a higher propensity to lose electrons. This treatment was tested on different species of wood cut in different directions, and the team then found the most efficient option, radially cut spruce.
Volgens de wetenschappers maakt deze behandeling hun hout 80 keer efficiënter in het opwekken van elektriciteit dan natuurlijk hout, en zorgt het voor een stabiele output onder constante stress gedurende maximaal 1.500 cycli. Gevormd tot een vloer ter grootte van A4-papier, kan het materiaal voldoende elektriciteit opwekken om huishoudelijke led-verlichting, rekenmachines en andere kleine elektronica van stroom te voorzien.
Panzarasa said: "Our focus was to demonstrate the possibility of modifying wood with a relatively environmentally friendly procedure to have a triboelectric effect. Spruce is cheap, available, and has good mechanical properties. This method of functionalization is quite Simple and scalable on an industrial level. It's just an engineering problem."
Scientists are now working to improve their handling of wood to make it more eco-friendly and easier to apply as they work towards commercial application. To their advantage, the "dynamo" maintains the natural look and durability of wood floors, which could make it an attractive option for style-conscious designers in future smart buildings.
"The ultimate goal is to understand the potential of wood, beyond those already known, and to give wood new properties for future sustainable smart buildings," said Panzarasa. The research was published in the journal Matter.
