Power from the parquet floor

Researchers from ETH Zurich and Empa are working with the Bauwerk Group to develop a parquet floor that uses ecological raw materials, achieves the properties of oak and can also act as a sensor or microgenerator. The combination of modified poplar wood and piezoelectric Rochelle salt creates a recyclable high-tech wood that converts human footsteps into electrical signals. A building block for smart homes and energy-integrated architecture.

Instead of oak, which is becoming increasingly scarce, the project relies on poplar wood, a fast-growing, climate-tolerant deciduous tree that has hardly been used in the parquet market to date. Using “green chemistry” and the incorporation of lignin from the paper industry, the soft poplar wood is compressed and hardened so that its mechanical properties and surface quality are comparable to oak parquet

This development addresses two challenges at once. Securing the supply of wood under climate change conditions and substituting petroleum-based floor coverings with bio-based, recyclable products. For manufacturers, this also opens up the possibility of transforming regional, previously “second-rate” wood species into high-quality design flooring

Parquet sensor and energy source
The second innovative step lies in the integration of piezoelectric functionality. If the wood is elastically deformed when walking, electrical voltage is generated that is too low in its natural state to be of practical use. By embedding Rochelle salt, a by-product of wine production with a strong piezoelectric effect, in a specially structured wood matrix, a hybrid structure is created that delivers significantly higher voltages and yet remains recyclable

This “salt-in-wood” technology enables parquet slats that act as sensors themselves. They recognize footfall, presence or movement patterns and can generate enough energy to supply wireless sensors or signals locally

Applications from smart homes to airports
In the short term, the researchers are targeting sensor applications in smart homes, such as access monitoring on doors and windows or presence-dependent lighting and climate control. In the medium term, the focus is shifting to highly frequented areas such as airports, train stations, shopping centers and cultural venues such as the Tanzhaus Zürich, where millions of steps per year offer considerable potential for energy conversion

The big challenge now lies in scaling. Material processes, sensor integration, durability and costs must be industrialized in such a way that “Piezo-Parkett” is transformed from a demonstrator into a market-ready product family. A goal that is receiving a boost from industry partnerships and awards such as the nomination for the “Evergreen Prize for Innovation”.

Quelle Empa