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Michael Erwin
Ross Martin (Team Leader)
Tao Nguyen
Clifton Weng
Ursula Zangrilli
Drs. Chun and Dougherty
• Objective
• History
• Proposal
• Short Term Goals
• Long Term Goals
• Almost Everyone Uses Portable Electronics
• Palm Pilot (200 mW), MP3 Players (110 mW), Laptops (10 W)
• All run out of power in a matter of hours
Objective
• Design a device to generate electrical power from the human body
1) Various devices that convert human mechanical
to electrical energy
2) A circuit to harness this energy
• Use this power to charge the batteries of portable electronics
• Harness enough electrical power to charge a laptop battery
History
Tess Zangrilli
History

MIT option one:
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Figure 1: Shoe with
Piezoelectric
generators
1-2 mJ / step
History

MIT option 2

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Figure 2: Shoe with
magnetic generator
.23 Watts
History


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Inventor Ivan Sarich
US Patent #6281594
Transmit power from
foot to waist
Figure 3 – Patent Design
Figure
History

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Seiko Thermic Watch
Seeback Effect
History

Seiko Kinetic Watches

Kinetic Energy Storage Unit
 Components
Advantages
 Auto Relay

History

1.
2.
Environment
NASA: Micro-wave power receivers
Hitachi Central Research Laboratories:
Convert natural vibrations to electrical energy
History

UCLA, Heliomite Block Diagram
The Idea
Ross Martin
The Idea

Shoe based generator

Incorporates piezoelectric strips

Parallel and layered design

Each strip produces 40 volts peak-to-peak per
pulse

Final output is an AC voltage
The Idea
The Problem: AC waves cannot charge the battery directly
The Idea

Next step is AC->DC Conversion
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Pass AC wave through transformer rectifier
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Capacitor filter smoothes the wave even
further
The Idea

Converting the voltage for charging

Li-Ion batteries operate in specific voltage
range
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Fluctuations or overcharging are not desired

Same applies for current, though more flexible

Pulsing of charging can reduce overheating
Shoe Charging Circuit Schematic
The Idea

Circuit attached to heel/sole
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Phone can be held in standard hip holster
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Wire feeds power to battery being charged

Standard charging plug for phone
Costs
Tao Nguyen
Factors that affect cost
Type of shoe
 Number of piezoelectric strips utilized
 Number of components used in circuit
 other materials/devices

Cost Estimates
Piezoelectric strips:$7 per strip
 Circuit components:about $10
 Shoe:$35-60
 Total cost approximately $50-80

Future Goals
Complete the Circuit
Required Parts
 Calculations
 Size Considerations

Testing

Piezoelectrics
Stress
 Heat
 Pressure
 Output


Comparing with other materials
Complete Cost Analysis
Gain more Accurate Costs
 Compare Prices

Reports
Keep up with Reports
 Keep Professors up to date

Have a Circuit built by Summer
Questions?