Recently, Swiss researchers unveiled an innovation. They turned wood into a kind of piezoelectric sponge that could be integrated into a parquet capable of producing energy with our steps. In addition, this package would be biodegradable.
Delignify the wood to obtain tension
Many researchers are trying to find solutions to produce green energy in different ways. However, there is currently a underexploited renewable energy source, namely that produced by our steps. Some devices already exist, such as the installation of electromagnetic generators under the ground, but the efficiency of which is still very relative. In a statement published on March 15, 2021, EMPA and the Federal Institute of Technology Zurich (Switzerland) detailed an innovation combining simplicity and ecology: a piezoelectric generator.
Thanks to the piezoelectric effect, some materials are indeed capable of generating electricity during deformation. However, the wood is usually too stiff to induce a really significant tension. Swiss scientists have however succeeded in obtaining a spongy material by transforming balsa wood (Bombacaceae) by means of a delignification process.
Remember that delignification is nothing other than the action of removing lignin from wood. With hemicellulose and cellulose, it constitutes one of the three main components of wood. As part of this work, the researchers immersed the wood in an acid bath of hydrogen peroxide and acetic acid, which easily removed the lignin.
Simple and ecological
According to scientists, the result of this operation takes the form of a kind of small cubic wooden sponge only 1.5 cm square. However, it is possible to generate 0.69 volts by exerting pressure between your fingers. If the pressure remains very low (7.1 nanoamperes), it is sufficient to give this sponge the function of pressure sensor. By placing about thirty of these sponges between two sheets of copper and two wooden plates, it is thus possible to supply a monochrome LCD screen.
In addition, the scientists of the study discovered a another way to delignify wood in a more ecological way. Use the P mushroomflattened olypore (Ganoderma applanatum) allows to break down the lignin as well as the hemicellulose of the wood in a particularly gentle way. Finally, according to scientists, this innovation could be associated with the manufacture of parquet floors. By walking on this kind of unprecedented parquet, it would then become possible to produce renewable electricity.