Piezoelectric energy: Harnessing human movement to generate electricity

The piezoelectric plates They are an innovative technology that allows converting footsteps, jumps and other movements of the human body into electrical energyThe energy generated comes from the mechanical pressure applied to a piezoelectric material, which has the ability to generate an electric current when subjected to deformation or friction.

The most curious and often cited case is that of the sustainable nightclub in London, where the energy generated by the movements of the attendees powers part of the lighting and other electrical systems. These types of installations have begun to be implemented in urban environments with high pedestrian traffic, improving energy efficiency and reducing the carbon footprint.

How does piezoelectricity work?

The phenomenon of piezoelectricity is based on the capacity of certain materials to generate an electric current when a mechanical deformation is applied. When a piezoelectric material, such as quartz, is stretched or compressed, its atoms rearrange themselves, creating an electrical potential difference that can be channelled and harnessed.

This process has two main applications:

• Direct energy generation: The footsteps or steps of people in an environment, for example, generate small electrical currents that can be used to illuminate or power small devices.
• Production of electrical signals: This property has traditionally been used in devices such as cigarette lighters, where a spark is generated with each pressure.

Applications of piezoelectric energy

Piezoelectricity has a wide range of applications which position it as a key technology for modern, smart cities seeking to optimize energy efficiency.

Some of its main applications are:

• On floors in high-traffic areasCountries like Japan have begun installing piezoelectric plates in subway stations to convert the kinetic energy of millions of users into electricity.
• Smart roads:Israel has launched projects to use the passage of vehicles on roads as a source of energy. With each passing car, a small amount of electricity is generated, which can reduce the dependence on other energy sources in road lighting systems.
• Portable devices:Piezoelectric energy can be applied to power biomedical devices or wearables that benefit from human motion, such as the heartbeat or everyday movements.
• Public lightingPiezoelectric pavements have been developed that store the energy generated by pedestrian traffic to illuminate streets and avenues at night.

Materials used in piezoelectricity

The main piezoelectric materials are both natural and synthetic, which allows their availability and efficiency in different applications. These materials have in common an internal crystalline structure that lacks a center of symmetry.

Some of the most commonly used piezoelectric materials include:

• Quartz: Perhaps the best known, this crystal is capable of generating electricity when pressure is applied to it.
• Tourmaline: Used in pressure sensors and other electronic applications due to its stability.
• Ceramics: Titanates such as lead zirconate titanate (PZT) are very common in industrial applications due to their highly tunable piezoelectric properties.

Flagship projects and innovation

Around the world, there are several flagship projects that are taking piezoelectric energy to new frontiers. One of the most notable is the Movistar project at the Santiago Bernabéu Stadium in Madrid, where piezoelectric plates were installed under the stadium stands to generate electricity from the movement of fans. This energy powered a giant LED screen in a nearby village, allowing residents to follow the match live.

Another interesting case is that of Pavegen Systems, a London-based company that has installed piezoelectric tiles in various cities to use the energy generated by pedestrians for sustainable purposes. Their projects show the enormous potential of this technology to improve the sustainability of cities.

The challenge of efficiency in piezoelectricity

One of the main challenges facing this type of technology is the efficiency in converting kinetic energy to electricityThe amounts of electricity generated are relatively small compared to other renewable energy sources such as solar or wind. However, its durability, ease of integration with existing infrastructure and the possibility of combining it with other clean energies, position it as a valuable option for urban projects or devices that require little energy.

With a scenario where the cost of piezoelectric materials has been reduced thanks to the mass production of electronic components, The future of piezoelectricity is promisingAs production efficiency and costs decrease, their application in smart cities will continue to increase.

In short, piezoelectric energy It emerges as a viable and sustainable solution to take advantage of human and vehicular movement, especially in cities and high-traffic environments. Although there are still challenges in terms of improving efficiency, its great potential to complement other renewable energy sources, its integration into urban infrastructures and its capacity to generate electricity in densely populated spaces make it an attractive option for the future of urban energy.