Presented by:-Amal Mathew

ELECTRICITY BY WALKING

The New Indian Express

Vijayawada ,Saturday 13

February 2016

• Human walking carries a lot of energy,Theoretical estimates show that it can produce up to 10 watts per shoe,and that energy is wasted as heat.

• The advance could provide a source of power to people in remote areas and developing countries that lack adequate electrical power grids.

• This coild be especially useful for the military,as soldiers currently carry heavy batteries to power their radios,gps unit and night vision goggles in the fiels.

• To generate power from walking we can make use of two phenomenon1).reverse electrowetting effect2).piezoelectric effect

Introduction

Did you know that you can produce electricity by just walking?

20 watts

Did you know this fact!

The reverse electrowetting effect has been defined as "the change in potential difference between the solid and the electrolyte due to

solid-electrolyte contact angle

Reverse electrowetting effect

Conducting fluid

Thinfilm dielectric

Metal electrode

Youngs Equation

SOME BASIC TERMS

Surface energyContact angleWettingYoungs equation

σ sg =σsl+σig.cosθ

σ sg

σsl

σig

θ Contact angle

Surface tension of liquid

Interfacial tension between liquid and solid

Surface free energy

How this works

How perfomance can be modified

• More energy is generated when the conductivity of the fluid is more

• Electrode material of low conductivity is preferable

• Making the channel length more• Use more droplet ,there by we can increase The effective area

Challenges

• Energy produced is very less• Device manufacturing for practical purpose• Liquids exhibits saturation phenomenon

In piezoelectric material an applied mechanical stress will generate a voltage

Piezoelectric effect

Applied mechanical stress

Change in potential difference

A n exa m p l e

Bridge rectifier

Piezo electric material

capacitor

The storing energy can be calculated by this equation:-

E= ½ *CV²E= ½ *(22²)*22*10¯⁶=5.324*10¯³E=5.32 mj

E/step=5.32/60=8.866*10¯⁵ j =88.66 µj

My smart phone battery needs 5.7 whIe; 5.7 wh=5.7*3600 j =20520 j

So, to produce 20520 j energy, for that we have to walk 23 billion steps

Where it is useful?

www.Wikipedia.orgwww.nanomotion.comwww.explainthatstuff.comwww.rapidtables.comwww.instructables.comwww.makezine.comwww.hyperphysics.phy-astr.gsu.eduwww.wired.comwww.googlesciencefair.comwww.youtube.comwww.memsjournal.com

Bibliography

Thank YouAny Questions