Tony

TUESDAY SEPT 30/2008 Concocted idea for Project Innovation. Theme: Electrical Consumption of the OSC: Present and Future to be fragmented into 3 divisions: 1. Explore 3 exhibits: how much electricity do they consume, why do they consume so much, and how much is the OSC paying for it? 2. Energy Alternatives: where is the electricity coming from and what are some future alternatives the OSC can turn to? 3. Immediate Improvements: what are some policies/improvements that the OSC can implement immediately to cut down energy usage?

FRIDAY OCT 3/2008 The group met and determined Friday at 12:30 to be the weekly meeting time. The third division of the idea was modified to "Immediate Energy Alternatives" which will include a comparison of solar cells and a generator powered by parabolic mirrors focusing radiant energy.

SUNDAY OCT 5/2008 I investigated the current application of piezoelectric cells in Shibuya Station, Japan. This article alerted me to the fact that a smaller surface area of piezoelectric cells, each with a high efficiency rate may likely prove more advantageous than a larger surface area, each yielding a lower benefit:cost ratio. Article states that "a relatively large amount of electricity" is generated. However, no specific numbers were given. I also dug into the realm of contemporary piezoelectric elements, the most economical being PZT (Lead Zirconate Titanate). Further research highlighted the actual theory behind piezoelectric cells. Since the entire picture is not completely clear, I plan to contact a university professor or other authority.

MONDAY OCT 6/2008 Researched electrical output of piezoelectric platforms, knee braces, and shoes with Amber. Dug up an article studying piezoelectric generation: Piezoelectric Energy Harvesting with a Clamped Circular Plate: Experimental Study Kim et al. Journal of Intelligent Material Systems and Structures.2005; 16: 855-863. Study highlighted that the voltage is proportional to the pressure applied. However, no time values were indicated in study, providing no values of power.

TUESDAY OCT 7/2008 Spent lunch writing the proposal: Electricity Outlook on the Science Centre: Present and Future and posted on the Wired front page.

WEDNESDAY OCT 8/2008 Examined an excellent research paper from Virginia University regarding the electrical output of piezoelectric cells. Apparently, storing the generated electricity in a nickel metal hydride battery yielded a higher efficiency rate than directly tapping into the electricity produced. Max output in terms of charging the hydride battery: I: 40mA V: 50V P: 2mW

SUNDAY OCT 12/2008 Read "Electric Power Generation Using Piezoelectric Devices" from Virginia Polytechnic Institute. Study references a paper by a 'Starner' who claimed 8.4W of electricity could be harvested from a shoe; will investigate that area in immediate future. Learned about a 'resonance input signal' of a charging battery. When at a frequency of 63Hz for button cells, the 40mAh battery took only 1 hour in contrast to the 1.5 hours from a random input signal. Finally, it would seem a 'capacitor-battery' set-up would be optimal. Two batteries can be used - one charging and the other delivering electrical output. This method seems to eclipse the 'direct capacitor' method since the batter(y)(ies) are capable of storing charge. Additionally, determined max output of charging the battery in previous entry to be max output of the capacitor method. Total charge of battery: 3600s x 40mA= 144C Total energy of battery: 144C x 1.2v = 172.8J Therefore, to charge it in an hour, the average power output must be: 172.8 J/3600s = 50mW P=IV would have been easier. However, energy of the cell and total charge might come in handy later on.

TUESDAY OCT 14/2008 Found Starner's Human-Powered Wearable Computing paper. Starner predicts a figure of 5W can be harnessed from the deflection of PVDF in a sole insert in shoes. However, another paper, Energy Scavenging with Shoe-mounted Piezoelectrics, has determined experimentally this value to actually be 8.4mW (This paper also contained some actual theory behind PZT electricity generation). The PZT electrical generation mounted in the heel to capture the striking motion displays a figure of 1.3mW. Starner did provide the key problem with a configuration centering around PZT platforms: their elastic modulus is abnormally high (4.9 x10^10 N/m). Therefore, the creation of the dipole with the PZT atom is notably difficult. Secondly, it would appear from the research up to this point, that the optimal piezoelectric configuration involves that of the 40mAh nickel hydride battery spewing out 50mW. After consulting with Scott and Paul, the final product of this section may be a small piezoelectric exhibit (with a voltmeter, ammeter, total energy production bar, etc.) situated on the walkway area between the second and third escalators. Plan to investigate the 'automobile compressor' used in the battery setup and work out specifics behind a possible exhibit.

The archway in the Great Hall right before the elevators leading down to level C seems an ideal spot to situate the exhibit. Thinking of planting a 1m x 2m piezoelectric platform underneath a TV screen with the exhibit info; the TV envisioned will be positioned similar to that of the screen displaying the information for the Emotion-chair down on level D.

MONDAY OCT 20/2008 Determined the final product of this section to be a model of the piezoelectric exhibit and a short video to be played on the TV screen. The final 20minute video will encompass a shot of the model and possibly, a short excerpt from the video. Will investigate the cost of the PZT used in the 50mW piezoelectric setup tomorrow. Additionally, research into the workings behind nickel metal hydride batteries will be a good idea.

TUESDAY OCT 21/2008 Researched the costs behind the piezoceramic sheets used in Sodano's "Electric Power Generation using Piezoelectric Devices." The square sheets are 72.4mm by 72.4mm and come in a range of widths (0.0105 inches/0.02625mm in used in the experiments). These sheets also display "low current leakage," increasing the efficiency of the piezoelectric system. Since the total surface area used for the exhibit will be roughly 1m by 2m, the total number of square sheets will be around 370. 100 sheets sell @ $35 each so in case of a contingency (malfunctioning sheets, broken sheets during installation, etc.), one will estimate the order of 400 sheets. The total cost would be around $14,000. To verify these are the exact sheets used in Dr. Angelo's paper, the product is a PSI-5H4E Piezoceramic (PZT) sheets from Piezo Systems, Inc. This name matches with the product info on http://www.piezo.com/prodsheet2sq5H.html.

THURSDAY OCT 23/2008 Pesonal Benchmark: The final product of this section will be a model of the proposed piezoelectric exhibit. In addition, the short video that is to be played on the TV screen will be a second product. The ultimate aim of this exhibit will be to raise awareness about the feasibility of future energy alternatives, specifically piezoelectricity. The research for the piezoelectric configuration has been completed in addition to most of the costs of the exhibit. Further research into the number of OSC visitors and the specifics behind the electrical setup should be completed by the first week of November. By the third week of November, the model exhibit should be completed. The short video should be finished come December. The original idea of the final 20minute amalgamating video has been abandoned. Instead, during the two weeks of December, I will invest time into the preparations for the interview and final PowerPoint presentation.

Suddenly very concerned about the actual power output of the exhibit. I plan to have some definite statistics but the automobile compressor used in the experiment neither corresponds to the frequency nor force of human footsteps. I plan to speak with Russell or another engineer in the building but in the worst case scenario, some estimation may be necessary.



Shown above is an image of the proposed piezoelectric exhibit. I plan to build a model of the area of the Great Hall shown above with the piezoelectric exhibit. I spoke to Russell about the circuitry involved and discovered that the strange symbol in Sodano's schematic diagram was a bridge rectifier, used to convert AC to DC output and to ensure the current flowed in a single direction. Else, when the battery is fully charged, the discharge will reverse back to the bridge rectifier and capacitor.

SUNDAY OCT 26/2008

Finally, I have obtained acceptable estimates for piezoelectric output on a human scale. Ironically, the answer was directly related to an item in the very first article I researched: the Japanese piezoelectric platform at Tokyo Station. At the north ticket gate in Marunouchi station, 6 piezoelectric platforms (1 square meter each) were set-up. From 4am to 2pm on the first day, the total output was 3609 J. The number of people passing through all of Tokyo Stations 12 ticket gates (downloaded a map of TS and counted) during the 3rd week was 800,000 and we will assume this weekly total of commuters to remain relatively constant (upon further research, the tally in 2007 was shown to be around 780,000). If we assume all 780,000 commuters walk through the platforms only once between 4AM and 2PM and distribute themselves evenly, and have not yet returned from work, school, etc. before 2PM, then the 3609J was generated over a period of 10 hours from 6 platforms as a result of the walking of 780,000/12 commuters. If we do the math, each of the 65000 commuters contributes 55mJ.

The reason for the above calculation was to verify one of the claims made by the carriers at Tokyo Station. Quote: "They (Piezoelectric platforms) can produce 70 to 100 milliwatt-seconds when someone walks through the gate." Evidently, 55mJ is lower than the purported average of 85mJ. We will, therefore, use this underestimate for two reasons: the nadir for electrical output in the exhibit and conscience's sake.

The key success to the OSC exhibit's electrical output is that if each visitor uses the same archway, he/she MUST walk through the piezoelectric platform twice: once to go down to the exhibits and the second time to exit the OSC. If we factor in that the OSC hosts traverse the piezolectric platform far more often than twice daily, we may treat each of their extra trips as 'additional visitors.' In 2006, the Ontario Science Centre saw a total of 1.4 million visitors. This figure comes out to around 3,850 visitors daily. Therefore, the piezoelectric exhibit will oversee a total daily output of (3,850x2x55mJ) or 422 Joules. This will be enough to fully charge 2 and a half nickel metal hydride button cell batteries everyday.

I have also sent an email out to Dr. Sodano, asking for an estimate as to how long he thinks it will take human footsteps to charge the nickel metal hydride battery. The next steps in the plan will be confirming that a large percentage of people pass through the central archway down to the exhibits. This will be done by a sample during Monday at lunch/spare. Additionally, further research into the extra trips of the OSC hosts and staff must be done to determine the number of 'additional daily visitors.' The specific circuitry of the exhibit must also be set-up. I realized last night that when I calculated the costs of the PZT platforms, I estimated the costs by determining unit price and multiplying it by the number of required pieces. This will not give me one entire piezoelectric platform but rather, numerous small platforms that must each be hooked up to electrodes and its own battery to work. Therefore, when calculating the price tag of the PZT plates, I will assume that a large platform will be equal to the cost of its cumulative constituents. However, since the total surface area of each of the 6 piezoelectric platforms in Tokyo Station were only 1 square meter, there is some leg room to be stingy.

The final discovery I have made today is a discouraging one. Due to the extreme number of commuters after the third week at Marunoichi Station, some of the piezoelectric platforms began to degrade and decrease in productivity. The total number of commuters at that point would have been 1,365,000 (calculated by 780,000/12 x 7 x 3). This number coincides with the OSC's annual number of visitors. Unfortunately, it would seem that the piezoelectric exhibit may require a fresh platform every year. Last week, I was talking to Doug and he spoke about a thin windowpane film that protected the glass from bullets. It seems a wild claim but I will do some digging into this 'film' to provide protection of the piezoelectric platform, ensuring that it does not break down even before its 1 year lifespan.

THURSDAY OCT 28/2008

Doug and I discussed how to best use spray-paint for my prototype. Quick summary: always wear gloves, go outside, and be upwind. I realized that a galvanometer must be installed instead of an ammeter since the current produced will be around 50mA. Made a couple of quick cuts to the PZT finances to bring down the original $14,000 to around $8000. Must find a way to improve the sheets' durability (0.267mm).

SUNDAY Nov 2/2008

Found a suitable NiMH battery: http://www.greenbatteries.com/gbulsdaaanimh.html. Specs: 1.2V, 800mAh. Those figures come out to produce a total charge of 2,880C and a final energy capacity of 3,456 J. This is roughly the same amount of energy produced in a week by the piezoelectric exhibit. My idea is to take the AAA battery out come Sunday night and install it in the robotic car trying to navigate its way out of a maze down in the Mars Exhibit. A little sign may be placed near the robotic car's exhibit info asking something along the lines of "Did you know you helped power this robot?" I feel using the piezoelectric exhibit's output in this manner will demonstrate the energy alternative's practicality albeit on a small scale.

Also found out the chemical reactions within NiMH batteries. It turns out the electrolyte in alkaline primary cells is the same for NiMH batteries: KOH. The oxidation reaction involves the increase in the oxidation state of Ni2+ to Ni3+: Ni(OH)2 + OH- >>> NiO(OH) + H20. The reduction reaction should consist of the reduction of hydrogen from 0 to -1: H20 + M >>> OH- + MH. The M is symbolic of a metallic alloy usually in the form XY5 where X is usually one of (Lathanum, Cerium, Neodymium, or Praseodymium) and Y one of (Nickel, Cobalt, Manganese, or Aluminum). It seems that these alloys are capable of forming hydrides that contain a large volume of hydrogen atoms relative to the alloy's own volume. Although NiMH batteries do contain a memory effect, it seems that the drawback is not as pronounced as it is in NiCD batteries. Additionally, since full charges and discharges occur weekly, battery maintenance should not be an issue.

The last significant obstacle in the exhibit's proposal is the electrical set-up. Russell explained the purpose of the bridge rectifier but I still can't figure out why the capacitor is placed in parallel with the battery. Since the electricity from the piezoelectric exhibit will power the Mars Robot, no TV will be installed in the ceiling to play an amusing video on piezoelectricity. However, the galvonometer, voltmeter and total energy bar meter will definitely be installed in addition to a less-technical explanation of piezoelectricity.

FRIDAY NOV 7/2008

The fragility of the piezoelectric sheets has been solved: ditch the sheets. Instead, circular piezoceramic elements of approximately 3cm in diameter will be used, as in Marunouchi Station. There, 480 circular elements (covered with rubber matting) were stationed in an area of 1 square meter, protected by rubber in the interstitial sites:

http://www.japanfs.org/db/2073-e (CIRCULAR ELEMENTS PDF) http://www4.fct.unesp.br/dmec/dincon2008/artigos/11/01-marcela.pdf (CONFERENCED PDF)

This concept can also be applied to the exhibit. However, upon research, it seems that these circular elements are quite expensive: a quantity of 100 costs $3000. To mimic the 480 elements, about $18,000 would be necessary. The important thing to remember though is that most of the commuters at Tokyo Station took maybe two or three steps on the piezoelectric mat. Therefore, to use a total of 480 elements would be superfluous. I propose instead that the exhibit be far more attractive by having imprints of footsteps on the square meter area and only station the circular piezoceramic elements in the areas corresponding to the footprints. This way, the exhibit will remain economically viable and engender curiosity from passerbys. I personally have quite large feet and upon measuring the dimensions, a 15 cm by 30cm area is sufficient for one footprint. Since most adults take two footsteps to traverse 1 m and most children take 3, there will be 6 such footsteps in one lane going down to level C and another 6 in a second lane coming back up to level B. As each of these 12 footprints can host approximately 18 elements (3 by 6), a total of about 216 elements are necessary. Overall, this translates to a value a little over $6,600.

Costs can be found here: http://www.piezo.com/prodsheet3disk5A.html#priceinfo

The fragility of the piezoceramic plates has been resolved in such a manner that the desired durability is achieved while also reducing the exhibit expenses. I will upload a picture of the floor arrangement later today. Last two things left in the research section are 1) the energy consumption of the robot down in the Roving Mars Exhibit and 2) the number of 'additional visitors' as a result of the numerous programs of OSC hosts.

SATURDAY NOV 8/2008

I spoke with Maria and another host at the Information Booth on Level D. Unfortunately, most of the OSC hosts do not even pass through the Level B archway, as they enter the building via the back and remain in the host area/level D for most of the day. Therefore, the number of visitors will be assumed to be the only people to contribute to the exhibit and the daily energy generated will be a minimum.



The above is the proposed design for the "Piezo-Power Gate." The Ammeter/Voltmeter/Power Bar will also be situated on the right archway (that is not visible due to the perspective drawing). The Power Bar will actually be an analog Casio clock that has been slightly modified and will be powered by a single rechargeable battery. The hour hand will be elongated and will be a thick red hand. The minute and second hands will not be present. The clock will have a black background.

There will be a circular black piece with a slit as thick as the width of the red hour hand. Then, when someone turns the handle such that the slit in the circular black piece is directly above the red hour hand, the red hand will be visible. There will be a linear conversion of the number of joules produced every hour such that 10 o'clock (when the OSC opens), the power bar is at 0% and at 5 o'clock (when the OSC closes) the power bar is at 100%.

The explanation of the exhibit info is difficult to situate. It must not interfere with the normally congested traffic of the Level B archway (now exacerbated by the Piezo-Power Gate). I propose for the exhibit's information to be placed on the ground a little past the Gate, preventing the visitors from remaining in the archway and blocking the passage of others. The exhibit information must be concise and simplified; visitors must read it quickly, understand what has happened, and immediately proceed down the escalators. However the information should also be aesthetically pleasing at the same time. Therefore, I propose a stick-and-ball diagram of the PZT molecule, showing that when the central atom (Pb/Zn) oscillates, the unit cell's neutrality is disrupted and a voltage is produced.

Lastly, there should be a sign advertising the "PIEZO-POWER GATE" hung from the ceiling behind pillars but underneath the "To Exhibits" board so that the Piezo-Power Gate text is still visible even at a distance. Will begin construction of the model this weekend. YES.

MONDAY NOV 10/2008

All save two pages of my first Powerpoint Presentation draft:

I have discovered the ultimate flaw to the exhibit proposal: the continuous replacement costs. I had initially assumed that 65000 commuters/day x 21 days would result in the number of commuters required to degrade the piezoelectric platform. However, this number is the total number of people passing through 6 platforms and therefore, erroneously assumes the piezoelectric platform to have a durability of 6 times the actual. It takes only 210 000 visitors to degrade the platform and therefore, the OSC would require 7 replacements per annum translating to about $45 000 in replacement costs every year.

TUESDAY NOV 11/2008

Still considering the final key points of the 'summary' page: Other than that, the first draft of the Piezo-Power Gate Powerpoint (what a mouthful) is done. To investigate: performance of degraded piezoelectrics. Reflecting back, it's ironic that PZT is already doped to try and enhance its durability.

In other news, base for my model has been found and completed. Model construction to begin this weekend.

Suddenly decided to post all used references (that were bookmarked on my computer):

WEDNESDAY NOV 12/2008

Walter Stoddard has yet to reply to my email ergarding the power supply of the robot down in the maze in Roving Mars. He should be returning this morning. Once the replacement period of the batteries is known, a use-recharge recycle period can be determined.

SUNDAY NOV 16/2008

Began building the Piezo-Power Gate model. Pillars and top beam have been completed: The floor plan, present on the base board, has been written in pencil and consequently, is very difficult to see.

THURSDAY NOV 21/2008

Walter Stoddard (in charge of exhibit designs or so the hosts say) sent me a reply to the Robing Mars Robot's power supply. In total, there are 6 AA batteries and a lith-ion battery behind the robot's camera. Both supplies are replaced at the beginning of each day.

SATURDAY NOV 22/2008

No progress so far on the investigation of degraded piezoelectric cells. I will see if Matt knows anything about them on Monday. The back beam, garbage can, and 'fire hose' area of the model are now complete. I am going to Canadian Tire for spray paint tomorrow.

SUNDAY NOV 23/2008

Picked up black spray paint at Wal-Mart for $1.97. Update on the model:

TUESDAY NOV 25/2008

Have completed the garbage can and fire hose area. Will upload picture when I get home. Talked to Matt today. No advancement on degraded piezoceramics.

SATUDAY NOV 30/2008 Finished the Piezo-Power Gate Logo in addition to the 'Energy Tip of the Day' and the 'Did You Know' ads on the right pillar.

TUESDAY DEC 2/2008 The exhibit explanation and PZT diagram have been completed. Additionally, the ammeter and voltmeter have been palced on the insides of the pillars. Stage 7 will likley be the finished product. Only the "Power Bar" remains.

SATURDAY DEC 6/2008 The design for a power bar is as shown below: HOORAY! The Piezo-Power Gate Model is finally complete. Here is a picture of Stage 7: And the completed model:

SUNDAY DEC 7/2008 Presentation version of the Piezo-Power Gate: