The Power in Your Footsteps
All across the globe, cities and scientists are looking for opportunities to raise awareness for renewable energy and shift people’s interest from using harmful energy sources to clean ones. This is, basically, the reason why energy professionals are working with various ways, even tapping into the mechanical energy that humans consume in their everyday lives. For instance, an average metro station during rush hour produces a huge amount of kinetic energy. Dance floors at nightclubs, football grounds, streets on busy times – producing energy from human activities in these public areas makes a huge sense.
Looking at the potential kinetic energy that people produce from opening doors to climbing steps, it proves hopeful that scientists begin to move their efforts towards maximizing energy from human activities. Recently, researchers have developed new technologies to convert mechanical energy from footsteps into electricity such as footwear embedded harvesters on shoes and the piezoelectric effect on footfall tiles.
Footwear Embedded Harvesters
This technology was developed by researchers Tom Krupenkin and Ashley Talor from University of Wisconsin – Madison. With the method they call as reverse electrowetting, they were able to generate electricity from footsteps. So, how is this possible?
Instead of converting electrical energy into mechanical, the researchers applied motion to generate electricity. This was made possible by dropping liquid between the electrodes that spread in the dielectric film. Both the droplets of liquid and the electrodes are connected to an external electrical circuit. Due to external movements, the edges between the drops of liquid and the electrodes decrease. With this, electrical charge is released and flows back into the circuit, thus, generating electrical current.
Moreover, converting footsteps into electricity requires another element. The researchers propose the use of footwear embedded harvesters, in which a millimeter wide and a 4-meter long tube contains both the droplets and electrodes. This device could be incorporated in the sole of the shoe and could generate up to 10 watts of electricity, enough to charge a mobile phone or a laptop. However, these shoes are not yet available in the market. It would take another two years, at least, to develop the technology.
Piezoelectric effect
This technology, the piezoelectric effect, has been alive for more than 130 years. It was discovered by brothers Jacques and Pierre Curie in 1880, that placing crystals under pressure generates an electrical charge. Today, this technology is incorporated in public places such as football fields, pavements and school corridors to generate power. One company – Pavegen, has made this possible with their deflecting pad in a soft ground surface, that is usually found in playgrounds. It can produce up to 7 watts of energy in every footstep, thus, able to power lights and other small devices for minutes.
To make sure that the technology matches its supply with demand, it should be installed in areas with high traffic, just like how Pavegen installed 200 kinteic tiles into a football pitch in Morro da Mineira. They work from day until night, alongside solar panels in order to power lights on a full battery for up to 10 hours.
Wasted Footsteps – No More
In an average, a person walks about 40,000 steps in a day. These steps have a lot of potential in harnessing energy and in the near future, they will never be wasted again. With all the ambitious plans in renewable energy, technologies could be applied to other areas where people expend their physical activities, like treadmills on the gym and many more. In time, people can power their mobile devices and other portable gadgets with their own mobility. Indeed, there is power in the people’s footsteps.
