Scientists have developed technology that can turn footsteps into electricity.

By tapping into an unexpected energy source, wooden flooring, researchers from Switzerland have developed an energy-harvesting device that uses wood with a combination of a silicone coating and embedded nanocrystals to produce enough energy to power LED lightbulbs and small electronics.

This device, called a nanogenerator, is based on sandwiching two pieces of wood between electrodes. The wood pieces become electrically charged owing to contact and separation when stepped on via a phenomenon called the triboelectric effect. This effect occurs when electrons can transfer from one object to another, akin to the static electricity produced when you rub a balloon on your hair for a few seconds.

If a material is tribo-positive it tends to lose electrons, and if it is tribo-negative it tends to attract electrons, said the senior study author, Guido Panzarasa, a group leader in the professorship of wood materials science located at Eidgenössische Technische Hochschule Zürich and the Swiss Federal Laboratories for Materials Science and Technology Dübendorf.

“Wood doesn’t have a strong tendency to lose nor attract electrons. As such, wood is a terrible triboelectric material, but wood is an excellent building material,” he said, noting that it is also beneficial given the material is a natural and renewable resource that also stores carbon dioxide.

To boost wood’s triboelectric properties, the researchers coated one piece of it with a common silicone that gains electrons upon contact, while the other piece was embellished with nanocrystals that have a tendency to lose electrons. After testing different types of wood, they found that radially cut spruce generated 80 times more electricity than natural wood.

Using a wood floor prototype with a surface area slightly smaller than a piece of A4 paper produced enough energy to drive household LED lamps and small electronic devices such as calculators, the researchers found. They successfully lit up a lightbulb with the prototype when a human adult walked upon it, according to the paper published in the journal Matter.

“In the future we may make a floor with these kinds of devices and the amount of energy could be produced by people just walking,” said Panzarasa. “Our focus was to demonstrate the possibility of modifying wood with relatively environmentally friendly procedures to make it triboelectric. Spruce is cheap and available and has favorable mechanical properties.”

Nick Jenkins, the leader of the center for integrated renewable energy generation and supply research group at Cardiff University, suggested the typical application of such a device could be powering an Internet of Things device. (SD-Agencies)