self charging gadgets

Self Charging Gadgets

Rishi Dua, Harsh ParikhTeam Teknovates, IIT Delhi

IBM Technology Web Contest 2011Supervisor: Dr. Shouri Chatterjee

Rishi, Harsh (Team Teknovates, IIT Delhi) Self Charging Gadgets 1 / 7

Self Charging GadgetsIntroduction

When we press a key on our mobile phone, a part of the energy we apply isused to press the key and most of it gets dissipated. The essence ofself-charging gadgets lies in the fact that they would capture this energyusing a piezoelectric layer and use it to charge the gadget that we areusing.


Self Charging GadgetsIntroduction

Piezoelectric materials are materials that physically deform in the presenceof an electric field, or conversely, produce an electrical charge whenmechanically deformed. This effect is due to the spontaneous separation ofcharge within certain crystal structures under the right conditionsproducing an electric dipole.


Self Charging GadgetsWorking

A thin piezoelectric layer is fitted below the keypad of the gadget (likea mobile phone)

When we press the button of the gadget, mechanical stress isproduced in the piezoelectric material.

Due to this stress, electric potential difference is generated.

Thus this Voltage is used to Charge the gadget.

This helps sustaining battery for long time and also may eliminate theneed of chargers.


Self Charging GadgetsAdvantages of using piezoelectric substances

No external source required. Charge gadget purely on the basis of ourMechanical Force

Voltages of 2 to 10 volts, sufficient to charge the gadget

No need for mechanical limit stops. Can be designed to exhibit verylittle mechanical damping

Highest energy density compared to any other method of chargingthat we could possibly imagine like solar energy, temperaturevariations etc.

No device replacement: Existing mobile phones can be fitted with apiezoelectric layer.

The self-charging gadget helps by increasing battery time duration.

Cost effective: PZT is cheap and easily available.

Environment friendly, as it helps saving electricity.


Self Charging GadgetsFeasibility and Cost Analysis

Instead of PZT bulk, use PZT thin films. We arranged the PZT thinfilms one on top of other with metallic layers in between so that theVoltage generated by each layer adds up and thus sufficient voltage isavailable to charge the gadget.

PZT is cheaply available and 1000s of PZT films can be made easilyby mechanical hydraulic presses in any laboratory, just as we made itin Ceramics Laboratory. The marginal cost it would add to thecurrent price of mobile phones is negligible compared to the utilityand energy-savings it would provide.

Acoustic noise and Temperature difference do not provide sufficientenergy and solar charging is a costly alternative. Piezoelectriccharging provides the highest energy density.
