As illustrated, footsteps on functionalized wood floors can generate enough electricity to power small devices. Photo by Sun, et al./Matter
Sept. 1 (UPI) -- Scientists in Switzerland have developed a new type of wood flooring that generates power when it's walked on.
Researchers were able to turn floorboards into a nanogenerator by layering pieces of wood and electrodes. The team of scientists described their feat in a new paper, published Wednesday in the journal Matter.
When the layers of functionalized wood are stepped on, they become momentarily electrically charged. This pattern of electrical connection and disconnection, as the boards are stepped on, produces a phenomenon known as a triboelectric effect, which enables the flow of electrons.
The feat would have been a whole lot simpler with some other material besides wood.
"Wood is basically triboneutral," senior author Guido Panzarasa said in a press release.
"It means that wood has no real tendency to acquire or to lose electrons. So the challenge is making wood that is able to attract and lose electrons," said Panzarasa, a material scientist and professor at ETH Zurich and the Swiss Federal Laboratories for Materials Science and Technology.
Panzarasa and his colleagues were able to solve the problem by coating one of the wood layers with polydimethylsiloxane, a type of silicone that easily acquires electrons.
In the other layer of wood, scientists embedded nanocrystals called zeolitic imidazolate framework-8, which willingly loses electrons.
Researchers also tested a variety of wood types to see which paired with the two coatings to yield more powerful triboelectric properties.
Tests showed radially cut spruce, when treated, produced 80 times more electricity than natural wood. The wood-based nanogenerator performed efficiently for up to 1,500 cycles.
To demonstrate their technology's potential, the researchers used a floorboard generator no bigger than a piece of paper to turn footprints into electricity and power a lightbulb. In a home, the flooring could be used to power lights and small electronics.
"Our focus was to demonstrate the possibility of modifying wood with relatively environmentally friendly procedures to make it triboelectric," said Panzarasa.
"Spruce is cheap and available and has favorable mechanical properties. The functionalization approach is quite simple, and it can be scalable on an industrial level. It's only a matter of engineering," Panzarasa said.
Scientists are currently testing different treatment to find the most eco-friendly options for the use of wood-based nanogenerators in the floors of residential homes and smart buildings.
"Even though we initially focused on basic research, eventually, the research that we do should lead to applications in the real world," said Panzarasa.
"The ultimate goal is to understand the potentialities of wood beyond those already known and to enable wood with new properties for future sustainable smart buildings," Panzarasa said.