Presentation on the idea of self charging gadgets. Team Teknovates was one of the top 10 teams from India to present in the finals of IBM Technology Web Contest 2011. Visit http://www.rishidua.com/self-charging-gadgets-ibm-technical-web-contest/ for more information.

1. Self Charging Gadgets
Rishi Dua, Harsh Parikh
Team Teknovates, IIT Delhi
IBM Technology Web Contest 2011
Supervisor: Dr. Shouri Chatterjee
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2. Self Charging Gadgets
Introduction
When we press a key on our mobile phone, a part of the energy we apply is
used to press the key and most of it gets dissipated. The essence of
self-charging gadgets lies in the fact that they would capture this energy
using a piezoelectric layer and use it to charge the gadget that we are
using.
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3. Self Charging Gadgets
Introduction
Piezoelectric materials are materials that physically deform in the presence
of an electric

4. eld, or conversely, produce an electrical charge when
mechanically deformed. This eect is due to the spontaneous separation of
charge within certain crystal structures under the right conditions
producing an electric dipole.
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5. Self Charging Gadgets
Working
A thin piezoelectric layer is

6. tted below the keypad of the gadget (like
a mobile phone)
When we press the button of the gadget, mechanical stress is
produced in the piezoelectric material.
Due to this stress, electric potential dierence is generated.
Thus this Voltage is used to Charge the gadget.
This helps sustaining battery for long time and also may eliminate the
need of chargers.
Rishi, Harsh (Team Teknovates, IIT Delhi) Self Charging Gadgets 4 / 7

7. Self Charging Gadgets
Working
A thin piezoelectric layer is

8. tted below the keypad of the gadget (like
a mobile phone)
When we press the button of the gadget, mechanical stress is
produced in the piezoelectric material.
Due to this stress, electric potential dierence is generated.
Thus this Voltage is used to Charge the gadget.
This helps sustaining battery for long time and also may eliminate the
need of chargers.
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9. Self Charging Gadgets
Advantages of using piezoelectric substances
No external source required. Charge gadget purely on the basis of our
Mechanical Force
Voltages of 2 to 10 volts, sucient to charge the gadget
No need for mechanical limit stops. Can be designed to exhibit very
little mechanical damping
Highest energy density compared to any other method of charging
that we could possibly imagine like solar energy, temperature
variations etc.
No device replacement: Existing mobile phones can be

10. tted with a
piezoelectric layer.
The self-charging gadget helps by increasing battery time duration.
Cost eective: PZT is cheap and easily available.
Environment friendly, as it helps saving electricity.
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11. Self Charging Gadgets
Feasibility and Cost Analysis
Instead of PZT bulk, use PZT thin

12. lms. We arranged the PZT thin

13. lms one on top of other with metallic layers in between so that the
Voltage generated by each layer adds up and thus sucient voltage is
available to charge the gadget.
PZT is cheaply available and 1000s of PZT

14. lms can be made easily
by mechanical hydraulic presses in any laboratory, just as we made it
in Ceramics Laboratory. The marginal cost it would add to the
current price of mobile phones is negligible compared to the utility
and energy-savings it would provide.
Acoustic noise and Temperature dierence do not provide sucient
energy and solar charging is a costly alternative. Piezoelectric
charging provides the highest energy density.
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