Four years ago, Delhi-based youngsters Mohak Bhalla and Anand Gangadharan - two X graders from Delhi decided to experiment a bit with their shoes and the Physics they were learning at school then. In three months, their ideas transformed into a device that they call the Walkie Mobi Charger. Now what is this device all about, you may wonder. This tiny device which easily fits in your pocket can charge your mobile phone using the kinetic energy produced by walking.

This charger claims to charge your phone 20 per cent faster than your standard charger.

While Mohak is pursuing BTech from Bharati Vidyapeeth’s College of Engineering, Delhi, Anand is doing the same at the Vellore Institute of Technology, Chennai. The young innovators are working on upgrading the device for the last four years with the hopes of introducing it in the market in another year or two.

“When we were brainstorming for the project we came across stories of how a country abroad used electricity generated by the footsteps of commuters to light up the work stations and platforms. It motivated us to think—why don’t we use a concept like this that could help individuals generate electricity for themselves, while also helping them to stay fit by walking?” said Anand on a report.

Another source of inspiration was the idea of how individuals could reduce their carbon footprint by turning to a sustainable way of generating electricity.

But why mobile phones? “When we were building it four years ago, we noticed how people from all age groups, especially the youth, were hooked on to their phones 24×7. We wanted to make a device that could be marketed in the long run, a product that would have some actual use. So we thought, why not give them an incentive while keeping them fit and increasing their love for the outdoors?” said Mohak.

The journey wasn’t easy. They created three prototypes, the designs for two of which were rejected on the paper itself. But they kept going. The school and their families continued to motivate them to give their idea another chance.

Three months later, they had a small prototype of the model ready, a device that can be strapped onto both legs. The generated electricity gets stored in a battery which charges your phone. Anand and Mohak are working together to refine the model and make it even more compact.

They made their first charger entirely of scrap material. The production cost came up to Rs 2000. They say that if it is manufactured in bulk, the price per unit will drop to Rs 500. Anand adds optimistically, “The point is to keep it less expensive so that everyone could have access to it.”

How it work :

The device operates on the principle of Electromagnetic Induction. The components of the charger include a dynamo and a buffer mechanism. This mechanism rotates the dynamo to produce the electricity needed to charge the mobile phone, with the compression and relaxation caused by the heels of the user’s feet.

When we walk, our heels compress and relax, as they touch the ground and lift. Simply put, the device uses the energy generated by this pattern to charge your phone.

When the friends tested the device, the electricity output generated from both feet was higher than the general output.

They are now working on an upgraded model while also aiming to make the newer version wireless. Yet to be tested, they are hopeful that the advanced circuit will be able to not only charge phones faster but also let it function as a power bank, which can charge the phone even when you have stopped walking.

The design that they are now working on will also make the device suitable for other devices in addition to the phone. Even a laptop!