Design and Analysis of Power Generating Tiles

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International Journal on Mechanical Engineering and Robotics (IJMER)

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Design and Analysis of Power Generating Tiles

1Siddesh Siddappa D, ²Shaikh Aatif Ahmed

1Thakur College of Engineering and Technology, Kandivali Mumbai, 400101,

2M.H.Saboo Siddik College of Engineering, Byculla , Mumbai Email: ¹[email protected]

Abstract: Walking is the most common activity in human life. When a person walks, he delivers energy to the road surface in the form of impact, vibration, sound etc., due to the transfer of his weight on to the road surface, through foot falls on the ground during every step. This energy can be tapped and converted in the usable form such as in electrical form. In order to develop a technique to harness footstep energy, we are developing a foot step electricity generating device.

This device, if embedded in the footpath, can convert foot impact energy into electrical form. The working principle is, when pedestrian steps on the top plate of the device, the plate will dip down slightly due to the weight of the pedestrian. The downward movement of the plate results in compression of the piezoelectric material fitted in the device, to produce electrical energy.

The device was operated by persons walking over to it.

However, if there is continuous movement of pedestrians over the device, a large amount of power will be produced.

In this research a prototype of the power generating tiles is developed and studied under varying loading conditions to investigate the feasibility of the technology.

Index Terms — Power generating tiles Piezoelectric, renewable energy.

I. INTRODUCTION

In this project we are generating electrical power as non- conventional method by simply walking or running on the foot step. Human-powered transport has been in existence since time immemorial in the form of walking, running and swimming. This project uses piezoelectric sensor. Simply stated, piezoelectric materials are crystals that generate electricity when compressed or vibrated. They have the unique opposite property of generating a stress when voltage is applied to them. Due to advancements in micro-electronic systems many consumer devices have decreased in size. Smaller electronic systems require less power to operate. As a result, solid-state multilayer piezoelectric generators have become a feasible power source for some applications. Current applications for multilayer piezo

generators are energy sources for munitions and wireless sensors, such as sensors that monitor tire pressure in automobiles. One of the most common applications of piezoelectricity is in the electric cigarette lighter. Other common applications include sensors on electric guitars like pick-ups and contact microphones, ultrasound machines, sonar wave detection and generation devices, engine management systems in cars, loudspeakers, fuel injectors for diesel engines and quartz clocks In this case the main concept is to convert mechanical energy into electrical energy gaining higher electrical generation. The control mechanism carries the piezoelectric sensor, A.C. ripples neutralizer, unidirectional current controller and 12V, 1.3 Amp lead acid dc rechargeable battery and an inverter is used to drive AC/DC loads. Every time a person steps on the mats, they trigger a small vibration that can be stored as energy. An average person, weighing 60 kg, will generate only 0.1 watt in the single second required to take two steps across the tile. But when we are covering a large area of floor space and thousands of people are stepping or jumping on them, then we can generate significant amounts of power. Stored in capacitors, the power can be channeled to energy-hungry parts of the station such as the electrical lighting system and the ticket gates..

II. LITERATURE REVIEW

One of the earliest practical applications of piezoelectric materials was the development of the first SONAR system in 1917 by Langevin who used quartz to transmit and receive ultrasonic waves [1]. One study used lead zirconate titanate (PZT) wafers and flexible, multilayer polyvinylidene fluoride (PVDF) films inside shoes to convert mechanical walking energy into usable electrical energy [2]. This system has been proposed for mobile computing and was ultimately able to provide continuously 1.3 mW at 3 V when walking at a rate of 0.8 Hz [3].Other projects have used piezoelectric films to extract electrical energy from mechanical vibration in machines to power MEMS devices. This work extracted ________________________________________________________________________________________________

ISSN (Print) : 2321-5747, Volume-4, Issue-1,2016 25

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a very small amount of power (<5 micro W) from the vibration and no attempt was made to condition or store the energy [4].

Similar work has extracted slightly more energy (=70 micro W) from machine and building vibrations Piezoelectric materials have also been studied to generate electricity from pressure variations in micro hydraulic systems [5].Recently a piezo electric tile capable of producing 40 V was devised and studied.[6]

III. PROBLEM STATEMENT

Proposal for the utilization of waste energy of foot power with human locomotion is very much relevant and important for highly populated countries like India and China where the roads, railway stations, bus stands, temples, etc. are all over crowded and millions of people move around the clock. Using piezoelectric to harvest vibration energy from humans walking, machinery vibrating, or cars moving on a roadway is an area of great interest, because this vibration energy is otherwise untapped. Since movement is everywhere, the ability to capture this energy cheaply would be a significant advancement toward greater efficiency and cleaner energy production

IV. MODE OF OPERATION

Fig. 1 shows the system model of the power generation and storage. When load is applied on the tile surface (blue) refer fig: 2 it moves in the downward direction.

 The projections on the tile surface come in contact with the piezo material (yellow) and hence apply force on it.

 The applied force produces stresses inside piezo material which will produce current.

 There is clearance of 0.5cm in between the springs (golden) and tile surface (blue) in order to provide free deflection.

 The spring (golden) is provided for stability as well as protecting the piezo material (yellow) from getting damage by excess load applied.

The base plate indicated in green color is fitted inside the frame (grey) firmly to provide support to piezo material while compression. Figure 8. shows the structure of power generating tile. Table No.III gives Specification of batteries

Figure 1. Power generation and storage model.

Figure 2. Mode of operation

V. ANALYSIS

As we know the pressure is directly proportional to amount of power generated P α Wt. Here we take the constant of proportionality as Қ, then the equation becomes

P = Қ Wt , Where, Қ- Constant of proportionality, Wt- weight

P- Power. We know that for Wt=50kg, we get the value of voltage V=4v and I =0.015A, Then P=V*I=4*0.015=0.06w, means we can say that for 50kg we get power (P) =0.06w

From this we can find the value of Қ Table I. Relation between P & Wt

Sr No P ( watt) Wt ( kg)

1 0.012 10

2 0.024 20

3 0.06 50

4 0.09 75

Қ=P/Wt=0.06/50=0.0012 .Table No.1 given above shows the relation between P & Wt. Fig 9. Shows the arrangement of piezo electric cells. Fig.10. shows the working prototype of power generating tile.

A. Varying Clearance VS Output Voltage:

The clearance verses o/p voltage graphs provide us with the result that, different loads required different values of clearance to achieve maximum voltage. The value of optimum clearance is 8.27mm. Figure 3 shows Varying clearance VS output voltage graphs.

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B. Static Load Vs Output Voltage graphs:

Static load graph for 2sec has the highest slope and the slope gradually decreases with the increase in duration of application of load. The value of maximum attainable static voltage is 4.1v. Figure 4 shows static load Vs output voltage graphs.

C.Dynamic Loading:

The dynamic loading graph Fig. 5 to 7 gives the variation of output voltage over varying time period.

The maximum attained output voltage in dynamic loading is 3.79v.

0 0.5 1 1.5 2 2.5 3 3.5 4 4.5

25kg Load 35kg Load 45kg Load

Clearance(mm)

O/p voltage(v)

Figure 3. Varying Clearance VS Output Voltage graphs

0.501 1.52 2.53 3.54 4.5

For 2sec For 3sec For 4sec

Load(kg)

O/p voltage(v)

Figure 4. Static Load Vs Output Voltage graphs.

This value of voltage is obtained for just a fraction of a second and varies continuously

0.2 0.4 0.6 0.8 1 1.2 1.4 1.6 1.8 2 2.2 2.4 0

1 2 3 4

Dynamic Load of 55kg

Time(sec) at Optimum Clearance

O/p voltage(v)

Figure 5.Output Voltage for the Dynamic load of 55Kg.

0.2 0.4 0.6 0.8 1 1.2 1.4 1.6 1.8 2 2.2 2.4 0

1 2 3 4 5

Dynamic Load of 60kg

O/p voltage(v)

Figure 6. Output Voltage for the Dynamic load of 60Kg.

0.2 0.4 0.6 0.8 1 1.2 1.4 1.6 1.8 2 2.2 2.4 0

5

Dynamic Load of 65kg

O/p Voltage(v)

Figure 7. Output Voltage for the Dynamic load of 65Kg

VI. VALIDATION AND TESTING

When the foot is placed on the tile the kinetic energy of the footstep is transferred to the piezo material. It then produces low voltage D.C. current which can directly be measured by multimeter. The D.C. current is then stored in a battery. As D.C. voltage cannot be used for powering an A.C. bulb, we create an inverter circuit to convert D.C. to A.C. It is connected to a transformer from which the appliance gets its power. Table No.II.

gives the properties of piezo sensors

VII. RESULTS, CONCLUSIONS AND FUTURE WORK

Electricity is produced due to pressing the piezo material enough to make the L.E.D. glow. Based on the results gathered in this investigation, the final prototype design do fulfil the engineering goal of generating electricity sufficient to power common electrical devices such as mobile phones.

Power generation is simply walking on the step. Power also generated by running or exercising on the step. No need fuel input .This is a Non-conventional system.

Battery is used to store the generated power.

This is applicable only for the particular place.

Mechanical moving parts are high. Initial cost of this arrangement is high. Care should be taken for batteries.

Foot step power can be used for agricultural, home applications, street-lighting. Foot step power generation can be used in emergency power failure situations.

Metros, Rural applications, etc. This can be used for many applications in rural areas where power availability is less or totally absent as India is a ________________________________________________________________________________________________

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developing country where energy management is a big challenge for huge population. By this project we can drive both A.C. as well as D.C. loads according to the force we applied on the piezo electric sensor.

More research is underway to increase the efficiency, optimality and durability of the device under varying conditions and for the suitability of the technology for the mass deployment and commercialization of the equipments.

REFERENCES

[1] K. F. Graff, “A history of ultrasonic,” in Phys.

Acoust.. New York: Academic, vol. 15, ch. 1.

1981.

[2] J. Kymissis, C. Kendall, J. J. Paradiso, and N.

Gershenfeld, “Parasitic power harvesting in shoes,” in Proc. 2nd IEEE Int. Conf.Wearable Computing, Los Alamitos, CA, pp. 132–139.

Aug. 1998.

[3] N. S. Shenck and J. A. Paradiso, “Energy scavenging with shoe-mounted piezo electrics,”

IEEE Micro, vol. 21, no. 3, pp. 30–42, May-Jun.

2001.

[4] P. Glynne-Jones, S. P. Beeby, and N. M. White,

“Towards a piezoelectric vibration-powered micro generator,” IEE Proc. Sci. Meas. Technol., vol. 148, no. 2, pp. 68–72, 2001.

[5] S. Roundy, “The power of good vibrations,” Lab Notes-Research from the College of Engineering, University of California, Berkeley, vol. 2, no. 1, Jan. 2002.

[6] kiran Boby, Aneela Paul K. et all, “The footstep power generation using piezo electric transducers,” International Journal of Engineering and Innovative Technology (IJEIT) Volume 3, Issue 10, April 2014.

VIII. APPENDIX

Figure 8. Structure of power generating tile.

Figure 9. Arrangement of piezo electric cells on the working model

Figure 10. Working prototype of power generating tile Table No. II. Properties of piezo sensors

Properties Values

RESONANT FREQUENCY 3.3 ± 0.5kHz

RESONANT IMPEDANCE 300 OHM max

STATIC CAPACITANCE 30nf ± 30% at

100Hz

ALLOWABLE INPUT

VOLTAGE 30 Vp-pmax

OPERATING TEMPERATURE

RANGE -20°C ~ 70°C

PLATE DIAMETER D=20 ± 0.1mm

CERAMIC DISC DIAMETER d=15 ± 0.3mm

PLATE THICKNESS t=0.10 ±

0.03mm

TOTAL THICKNESS T=0.22 ±

0.05mm

PLATE MATERIAL Brass

Table No.III Specification of batteries

Model RB405

Function VRLA Battery Dimensions 80*70*105mm(L*w*H

) Rated

Capacity 4V 0.5AH

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