1. RECOGNIZING OPPORTUNITYA) B)
SOURCE OF ENERGY C)
3.6 X 1016 KJ
D) BE HUMANE

2. THE POWER OF WALKING 1.3 mW 8.4 mW 5 W 8.4 W 8.4 mJ
PIEZOELECTRIC SOLE INSERTS
PIEZOELECTRIC HEEL INSERTS
● Flexible PVDF deflects 0.6 times/sec
● Highly durable
● Easy to cut into appropriate shape
● Semi-flexible PZT
● Takes advantage of greatest force
● Heel strike with 130% apparent mass
(1.5W) x (2 steps/sec x
0.6 steps/sec)=
(12.5%) x (67W)=
5 W
8.4 W

3. THE SODANO APPROACH ADVANTAGES: DISADVANTAGES:
● At resonant frequency, 40mAh NiMH 1.2V button cell charged in 1 hour
● With a random signal, 40mAh NiMH 1.2V button cell charged in 1.5 hour
● (144C x 1.2v)/3600s = 50mW
● Presents the piezoelectric setup
DISADVANTAGES:
● Accelerometer has a completely random frequency ( Hz)
● 185 PSI-5H4E sheets = $
● Extreme brittleness: 0.267mm thick
CAR COMPRESSOR
(ACCELEROMETER)
PSI-5H4E (PZT)

4. PIEZOCERAMICS: PZT
● “The direct piezoelectric effect” (Pierre & Jacques Curie in 1880):
Generating of an electric current by applying mechanical stress
● During WWII, the greatest class of piezoelectric elements shifted to man-made FERROELECTRICS:
1. Barium Titanate (BaTiO3B)
2. PZT (Lead Zirconate Titanate)
● PZT is most economical and efficient alternative

5. TOKYO STATION: MARUNOUCHI NORTH TICKET GATE
● OCTOBER 16 4:00 AM – 2:00 PM
● 785,801 daily commuters on average for the year 2007
KEY ASSUMPTIONS:
● We assume all 785,801 commuters undergo only a one-way commute to work, school, etc.
● Neglect any return-trips that occur 4AM and 2PM that would otherwise increase the number of ‘commuters’
● The same number of commuters walk through the platforms only once between 4AM and 2PM
● Distribute themselves evenly
3609 J IN 10 HOURS

6. LOCATING THE TICKET GATES
COMMUTERS AT MARUNOUCHI NORTH 1 2 3 4 5 6
The piezoelectric floor at Marunouchi North Gate 7
1) /6 PLATFORMS =
10,000 COMMUTERS
2) (3609/6) J / 10,000 COMMUTERS =
55 mJ PER COMMUTER 8 10 9 11 12

7. FINANCING
● 480 disc-shaped piezoelectric elements with a diameter of 30 mm
● 480 units x $30/unit = $14 400
● Only units that commuters apply mechanical stress on are productive
● Three pairs of footprints
● Two lanes: one proceeding down to Level D and the other proceeding up to Level B
x (3 x 6) x $30/unit =
$6 480
“The piezoelectric elements covering
the floor are commercially
available ceramic piezoelectric elements”
12 x (3 x 6) x $30/unit =
$6 480

8. A NiMh“green battery”:
SHIELDING AND OUTPUT
● Rubber matting surrounding the piezoelectric elements in the same plane
● Rubber matting below the circular piezoceramics and shielding them from above
PART A: Exhibit Output
● 1.4 million visitors/year = 3,850 visitors daily
● 3,850 x 2 x 55 mJ = 462 Joules daily
● 462 J x 7 days = Joules weekly
PART B: Battery Capacity
A NiMh“green battery”:
800mAh / 1.2V / AAA
● 800mA x 3600 s x 1.2 V = 3456 Joules

9. WHAT IS IT GOING TO POWER?
Current Power Supply:
● 6AA rechargeable batteries
● Lithium-ion battery (camera)
Batteries recharged at the end of every day
● 1 AAA Green battery would be supplied once every week
● Illustrate practicality of piezoelectricity on a small scale
● Power the Robot in the maze in the ‘Roving Mars’ Exhibit

10. THE BOMBSHELL WHAT IS THE RATE OF DEGRADATION?
●“After the 3rd week of the experimental period, production of electricity decreased due to a degradation in durability”
● The gargantuan number of commuters at Marunouchi North Ticket Gate eventually oversaw the breakdown of the piezoelectric platforms
WHAT IS THE RATE OF DEGRADATION?
commuters/day x 21 days = commuters
1.4 million/0.21 million ≈ 7 replacements per annum
7 x $6 480 = $ per annum

11. THE PIEZO-POWER GATE DESIGN
Ammeter A C
Voltmeter B B A
Piezo-Power Gate Sign C G
Power Bar D D E
Exhibit Info E F
Piezoelectric Platform F
NOVEMBER 8/2008
Electrical Output Info G

12. THE PIEZO-POWER GATE MODEL
Ammeter A
Voltmeter B
Piezo-Power Gate Sign C C G
Power Bar A D B
Exhibit Info E E D
Piezoelectric Platform F
Electrical Output Info G
DECEMBER 6/2008 F