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.
Under åren har forskare undersökt ett antal innovativa golvlösningar som kan generera elektricitet från mänsklig rörelse, inklusive keramiska plattor för inomhus- och utomhusbruk, och svampigt trä som förlitar sig på den piezoelektriska effekten för att generera spänning under mekaniskt tryck. Det här nya exemplet delar vissa likheter med ett annat som vi såg 2016, där forskare bäddade in cellulosananofibrer i trägolv och skapade en elektrisk laddning när de vibrerades genom den så kallade triboelektriska effekten.
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.
Enligt forskarna gör denna behandling deras trä 80 gånger effektivare för att generera elektricitet än naturligt trä, och ger en stabil produktion under konstant stress i upp till 1 500 cykler. Format till ett golv ungefär lika stort som A4-papper, kan materialet generera tillräckligt med elektricitet för att driva hushålls LED-lampor, miniräknare och annan liten elektronik.
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.
