Credit: iStock

Using piezoelectric technology in floors can help conserve energy by converting human energy into electrical energy


The following essay was a finalist in the BC Hydro Invent the Future Contest. For more information, visit InventTheFuture.ca

Imagine yourself at school, just before lunch. The bell rings, and the students pour out of the classrooms. They rush downstairs, feet pounding, eager to eat their lunch and spend time with their friends. You get caught up in the wave of people, and soon you too are pushing through the halls. How many people are treading on the floor, their shoes squeaking on the shiny marble? Hundreds, thousands? It certainly seems like an endless amount. What if all the human energy and force that was being exerted on the school floor could be turned into electrical energy. Think of the possibilities for all that energy! It could be used to power the lights in the classrooms, or to run the overhead projectors. It could power the computers in the computer lab, or run the ovens and microwaves in the cafeteria. The opportunities are endless!

Talia Albert
Age 15, Vancouver
Entry Name: Recycling for a Cure

Certain materials produce electricity when stress is applied, such as some ceramics and crystals. This electricity is called Piezoelectricity. How does piezoelectricity work, you may ask? Well, it really is quite simple. A piezoelectric crystal consists of an equal number of both positive and negative electrical charges, that are symmetrically distributed within the crystal. The crystal is therefore electrically neutral. When stress is applied, it causes the symmetry in the crystal to be broken. This asymmetry results in an electrical current. Even a tiny piezoelectric crystal, such as a 1 cm cube of quartz, can generate voltage around 12,500 V when force is applied. This is all very cool, but you might wonder how it can be used, and also, more importantly, how it relates to energy conservation. Piezoelectricity is actually already used in more ways than you might think.


You've just had a really hectic day at school, and to relax, you go to take a bath. While you're soaking in the raspberry scented bubbles, you decide to light a candle to help you unwind. You flick your thumb on the cold metal wheel of a lighter and it produces a flame. This process uses piezoelectricity. Later that day, when you finally arrive home you find that your parents have gone out for dinner and have left a pot of soup for your dinner. Your stomach is growling, so you turn on the stove to heat the soup. As you turn the dial on the front of the stove, it uses piezoelectricity to create a flame and light the burner. After dinner, you decide you need some music to listen to while you do your english homework. Your mp3 player is broken—who knew your mom would decide to wash your jeans without looking in the pockets first —so you crank up your dad's old record player. The vibrations from the needle are transferred by use of a crystal into sound energy, using...you guessed it: piezoelectricity.


Piezoelectricity is also already being used for energy conservation. In Rotterdam, the Netherlands, the floor of a new dance club called the Watt uses energy generated by jumps and vibrations and transforms it into electricity. The Watt, with its quirky setting, describes itself as the first sustainable dance club. The piezoelectricity generated by the dancing is used to power the light show in and around the floor. Another example of piezoelectricity being used for energy conservation is The East Japan Railway Company, or JR-East. They are working on technology that would generate electricity as commuters walk through a ticket gate containing piezoelectric elements. JR-East claims that this sort of human-powered electricity generation system, when combined with high-efficiency storage systems can serve as a clean source of supplementary power for the train stations. A final example of energy conservation using piezoelectricity is an invention by James Graham and Thaddeus Jusczyk, two MIT graduates, who used piezoelectricity in a similar way to those ideas described above. The “Crowd Farm” would harvest the energy of human movement in busy settings, like the motion of fans at a concert. Piezoelectricity would turn this human energy into electrical energy which would power the lights and the speakers. Greater movement of people could make the music louder. Talk about an electric atmosphere!


I believe that there are two main places where the use of piezoelectricity in floors would make a huge difference in energy conservation; in schools, and on highways or busy streets. If the floors of schools converted human energy into electrical energy, whenever anybody raced up the stairs, played basketball in the gym, or walked from one class to another, energy would be stored for later use in the school. Similarly, if the force exerted on roads or highways could be turned into electricity, when somebody drove their car to work or took the bus to school that energy could later be used to power streetlights or traffic lights.


In conclusion, although the use of piezoelectric crystals to produce electricity is not a new idea, we are only just beginning to discover the many possibilities for energy conservation that this substance may provide. Think of a piezoelectric floor like the recycling of the future. When we recycle materials, we process used materials into new products in order to reduce energy usage. This saves an incredible amount of energy. For example, recycling a single aluminum can saves enough energy to power your television for three hours or to run a 100-watt light bulb for almost four hours. Why not recycle human energy too? After all, we exert energy all the time, and almost none of it is converted into useable power. Doesn't that seem a bit wasteful to you?