RECOGNIZING OPPORTUNITY A) B) SOURCE OF ENERGY C) 3.6 X 1016 KJ D) BE HUMANE

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

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 (1-1000 Hz) ● 185 PSI-5H4E sheets = $7 316.75 ● Extreme brittleness: 0.267mm thick CAR COMPRESSOR (ACCELEROMETER) PSI-5H4E (PZT)

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

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

LOCATING THE TICKET GATES 65 000 COMMUTERS AT MARUNOUCHI NORTH 1 2 3 4 5 6 The piezoelectric floor at Marunouchi North Gate 7 1) 65 000/6 PLATFORMS = 10,000 COMMUTERS 2) (3609/6) J / 10,000 COMMUTERS = 55 mJ PER COMMUTER 8 10 9 11 12

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

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 = 3 234 Joules weekly PART B: Battery Capacity A NiMh“green battery”: 800mAh / 1.2V / AAA ● 800mA x 3600 s x 1.2 V = 3456 Joules

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

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? 10 000 commuters/day x 21 days = 210 000 commuters 1.4 million/0.21 million ≈ 7 replacements per annum 7 x $6 480 = $45 360 per annum

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

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