Scientists have created technology that converts footsteps into electricity.
Researchers from Switzerland discovered a way to harvest energy from wooden flooring. They have created a wood-based energy-harvesting device using a combination silicone coating and embedded nanocrystals. This allows them to produce enough power to power small electronics and LED lightbulbs.
The nanogenerator is made by sandwiching two pieces wood between two electrodes.
Wood pieces can become electrically charged due to contact and separation, a phenomenon known as the triboelectric effects. This is when electrons transfer from one object into another. It's similar to static electricity that you get when you rub your hair with a balloon for a few seconds.
Guido Panzarasa, senior author of the study, stated that a material with a tribo-positive tends lose electrons and a material with a tribonegative tends to attract electrons. Guido Panzarasa is the group leader at the Eidgenssische Technikische Hochschule Zrich and at the Swiss Federal Laboratories for Materials Science and Technology Dbendorf.
Wood is not prone to losing or attracting electrons. Wood is not a good triboelectric material. However, it is an excellent building material. He also said that wood is a natural, renewable resource that stores carbon dioxide.
The researchers used a common silicone to coat one section of wood with electron-gainening compounds. The other was coated with nanocrystals, which have a tendency lose electrons. They found that radially-cut spruce, a wood used for construction in Europe, generated 80 times more electricity per unit of wood than natural wood.
Researchers found that a prototype wood floor made from a smaller area than an A4 sheet of paper could produce enough energy to power small electronic devices like calculators and household LED lamps. According to the paper published by Matter, the researchers were able to light up a lightbulb using the prototype.
Panzarasa said that if you imagine making a floor using these types of devices, how much energy could people walk on it? Our goal was to show how wood can be modified in a way that is not harmful to the environment to become triboelectric. Spruce is inexpensive and readily available, and it has excellent mechanical properties.
Professor Nick Jenkins, the head of the centre of integrated renewable energy generation research group at Cardiff University was not involved in this research. He suggested that a typical use of such a device would be to power an Internet of Things device. If a continuous supply is required for lighting or other purposes, then the device would require continuous motion to supply the input power.
Panzarasa warned that this is proof-of-concept data and that the technology needs more work before it can be scaled up to industrial use.
Our focus has been on industrially-friendly improvements to the method. He said that we might have to sacrifice efficiency for easier wood modifications.
Even though the output of one device is not as high as that of the one we published above, the combination of multiple devices within a larger flooring unit will ultimately produce significant amounts of energy.
