SAMAR PRATAP NAYAK
SANDEEP KUMAR PANIGRAHI
SAROJ KUMAR BAL
UNDER GUIDANCE BY:
PROF. DURYODHAN SETHI
This project is designed to ensure that our cell phones
never run out of juice by letting us charge it while we are on
our daily walk and getting some exercise and thereby getting
two jobs done at the same time . The basic idea is about
converting a part of the bio-mechanical energy spent in our
day-to-day lives(while walking) into a usable form and storing
it to charge low-power battery operated device.
2. HOW DOES IT WORKS
4. PERFORMANCE OF THE
Walk-n-charge is one of the technologies used to charge the low-power operated devices like mobile
phone batteries, MP3 player batteries, etc while you walk.
Two technologies have been tested so far to convert energy used in walking into electrical power.
1. Uses of piezoelectric material.
2. Placing small electro-mechanical devices, such as a dynamo.
Use of piezoelectric material
• This gets compressed while you walk and generates a substantial voltage, which when combined with
appropriate electronics, can be used to charge a mobile phone battery.
• The piezoelectric device generates about 150 milliwatts of power as of now, which is not sufficient to run a cell
phone, but would be enough to charge the battery slowly.
By placing small electro-mechanical device
• It involves placing small electro-mechanical devices, such as a dynamo, in the heel of the shoe. The dynamo
spins every time your heel strikes the ground, thereby generating a small amount of current.
• The dynamo technology has the potential of generating much more power than piezoelectric material.
The mechanism involves three basic stages:
Conversion of mechanical to electrical energy
Storing the electrical energy
Using this energy to charge mobile phone
HOW DOES IT WORKS ?
Work n Charge is worn below the knee cap on one leg and a light string is attached to the other leg. The
strides taken help in pulling and retracting the string, which is further attached to a dynamo that generates
about 3.5 Watts; enough to charge low-powered devices like mobiles, MP3 players, GPS devices, etc
Walk-N-Charge is about converting a part of the bio-mechanical energy spent in our day-to-day lives (while
walking) into a usable form and storing it to charge low-power battery-operated devices.
Walking involves a change in relative displacement of around 35 cm between legs. This repeated linear
motion could be converted to rotary motion with the help of a pulley and string. Thus, the bio-mechanical
work is converted into mechanical form and eventually stored as chemical energy in batteries to store
The device is clamped on one leg using a Velcro strap and a hole lets out a Nylon string that is attached to
the other leg that helps in the conversion of the displacement into rotary motion.
Even a slight displacement pulls the string out, thereby rotating the pulley, which turns the central shaft. The
shaft is common to the gearbox, the dynamo and the recoil mechanism. So, when the displacement reduces,
there is a slack in the string, which is removed by the tension produced by the recoil system. Since the electricity
produced is bi-directional and contains spikes, an electronic circuit encompassing a rectifier and a filter converts
it into a unidirectional, spike-free wave and stores the energy produced in rechargeable batteries. This stored
energy is used as an input supply to mobiles with the help of different adapters.
PERFORMANCE OF THE CHARGER:
Each Walk-N-Charge is capable of generating minimum 3.5 Watts of power at normal walking
speed (4 km/h).
An intermittent walk of 20 minutes is sufficient to charge a mobile with around 1 hour talk time,
which can be considered as an average person’s phone usage for a day.
For a person with an average walking of half an hour per day, this device can generate 2 W/h of
ADVANTAGES AND FUTURE PROSPECTIVES:
Increasing the effectiveness of mobiles in rural india by providing a portable means of charging of
Helping military personnel charge their GPS devices and other low-power electronic gadgets while on the move.
Providing an alternate means to wall-based charging for MP3 players, mobiles, etc in cities, thereby, helping
today’s fast generation to move faster without mobile battery problems.
India has signed the Kyoto Protocol – an acknowledgement that we share the concern of global warming, which
also expresses our commitment to slow down climate change. Walk-N-Charge would just add to the efforts put in
by India in various innovative ways.
Charging your cell phone might soon be as simple as taking a walk around the block.
Hence, walk-n-charge is the best idea for battery charging. Even if 0.1% of the Indian population
uses this device, it can generate 1500 kW/h of energy and can help reduce carbon emission by
2.25 tonnes per day. Thus, Walk-N-Charge promises you a source of energy that is not only clean,
portable and inexpensive, but also charges your mobile while you get charged up!
1. Rocha. J.G, Gonçalves L. M, Rocha .P. F, Silva. M. P., And Lanceros-Méndez. S. (2010) “Energy Harvesting From
Piezoelectric Materials Fully Integrated In Footwear‟- IEEE Transactions On Industrial Electronics, Vol. 57, No.
3, March 2010
2. Faruk Yildiz Sam “Energy Harvesting From Passive Human Power “Houston State University International
Journal Of Innovative Research In Science, Engineering And Technology Vol. 2, Issue 7, July 2013