Friday, 11 July 2014

Electrolyte challenge hypothesis and variables

Independant variable:
Type of drink (orange juice or sports drinks)

Dependant variable:
Amount of electrolytes in drink.

The amount of electrolytes in the orange juice will be the same as in the sports drinks

Constant variable:
The amount of drink tested.

Water to fuel to water: Formulating Hypothesis

Independent variable: Use of cobalt-based catalyst

Dependent variable: Amount Molecular Oxygen Formed

Constant variable: Amount of water

Hypothesis: Examine water's usefulness as a renewable energy source by observing how efficient a cobalt-based catalyst can be at helping to form molecular oxygen.

Wednesday, 9 July 2014

Literature Review 3

Article 1

Data analysis

Solar cells are popping up on rooftops everywhere these days and are a model for clean, renewable energy. Did you ever look at those solar panels and wonder how we can get electricity produced by solar cells when the sun is not shining? It is a great question because solar panels do not produce electricity when it is dark outside. One strategy to overcome this challenge is to store the energy produced by solar cells during the day in the form of a fuel that can be used at a later time. In this science project, you will explore a cutting-edge method for storing renewable energy by breaking up water molecules into hydrogen and oxygen. The hydrogen and oxygen are fuels that can be burned in devices such as fuel cells to produce clean electricity when it is dark!

Main Objective: Examine water's usefulness as a renewable energy source by observing how efficient a cobalt-based catalyst can be at helping to form molecular oxygen.

Article 2

The future of energy supply depends on innovative breakthroughs regarding the design of cheap, sustainable and efficient systems for the conversion and storage of renewable energy sources. The production of hydrogen through water splitting seems a promising and appealing solution. We found that a robust nanoparticulate electrocatalytic material, H2–CoCat, can be electrochemically prepared from cobalt salts in a phosphate buffer. This material consists of metallic cobalt coated with a cobalt-oxo/hydroxo-phosphate layer in contact with the electrolyte and mediates H2 evolution from neutral aqueous buffer at modest overpotentials. Remarkably, it can be converted on anodic equilibration into the previously described amorphous cobalt oxide film (O2–CoCat or CoPi) catalysing O2 evolution. The switch between the two catalytic forms is fully reversible and corresponds to a local interconversion between two morphologies and compositions at the surface of the electrode. After deposition, the noble-metal-free coating thus functions as a robust, bifunctional and switchable catalyst.


The cobalt-based catalyst reacts with water so molecular oxygen can be formed. This in turn provides sustainable energy. The cycle is repeated.

Tuesday, 8 July 2014

Literature review 1

Article 1
Data Analysis/Conclusion:

My data concluded that water has a conductance of 1.11×10^-7 siemens. The conductance of orange juice is 0.62 siemens. The sports drink Gatorade has a conductance of 0.63 siemens. These results prove my hypothesis false. In accordance with prior knowledge, orange juice has almost no conductivity, and thus it is equivalent to the control group. Because a higher conductivity means a higher electrolyte count, sports drinks actually have a greater quantity of electrolytes than orange juice, and this is why my hypothesis was wrong. 
However, the difference in conductivity between Gatorade and orange juice is only a one hundredth. This means that there is very little reason to choose Gatorade over orange juice. Orange juice has vitamins like folic acid, calcium, and potassium, and other natural benefits such as the ability to prevent diseases, and improve a person’s circulation. Gatorade is, in part, drunk due to its well known brand name and reputation. In reality, with only a one hundredth difference between a natural drink containing many helpful vitamins and minerals, and one made of chemicals such as those that cause food coloring, it is not a incredibly hard to see which is more profitable to the body if drunk during exercise.
The only thing that I could have done differently in order to gain more accurate results is to have designed a better conductance sensor. The wires in the sensor repeatedly fell off of the tube and because of this I wrapped a small piece of masking tape around the tube so that the wires would not come off. When the tape got to wet, it would fall off, and had to be replaced with more tape. Also, the clips connecting the battery to the wires also often came loose, and thus they had to be constantly reconnected. Whether the faulty conductance sensor had any effect on the outcome of this experiment is unknown. It is quite possible however, that it was this problem which caused the small difference in conductivity between the sports drink and orange juice, and that their conductivities really were equivalent.
Article 2:

The electrolyte content of beverages was determined by passing a constant D.C. electric current between two electrodes in the beverage and recording the resulting flow of electric current in microamperes. The measured current is proportional to the electrical conductance, which is directly related to the electrolyte content of the solution. All assessments were done in triplicate at room temperature to minimize measurement error and the resulting data points were averaged for each beverage. Distilled water, which does not contain electrolytes, was used as a negative control in this experiment. Variables such as temperature, time of assessment, amount of beverage and electrode were held constant so to not impact the independent variable, which was type of beverage. The dependent variable, electric current, was used to calculate the conductivity of each solution as an indicator of the electrolyte content of the solution.

The original electrode design yielded small currents which were difficult to measure. Therefore, the electrode was redesigned with a greater surface area so that the currents produced were greater and more accurately measured. The results represent the data obtained from the improved electrode design (electrode 2). Overall, the individual readings were fairly consistent with little variability between the triplicate assessments of each beverage.

The beverages that yielded the highest conductance as measured in nano Siemens, and therefore exhibited the highest electrolyte content, were lime juice (374ns), apple juice (340ns), orange juice (292ns) and mixed berry juice (281ns). Gatorade Thirst Quencher had the highest conductance of all the sports drinks tested (243ns), but the amount was still less than the conductance of the fruit juices. The one fruit juice that had a low electrolyte content was Oceanspray pure cranberry juice (167ns). Additionally, fresh orange juice had similar electrolyte content to the frozen concentrate. Of all the beverages analyzed, tap water and Mountain Dew Voltage had the lowest electrolyte contents.


Electric Conductivity of Beverages Tested

Data Table 1

Data Table 1
Results obtained using electrode 1

Data Table 2

Data Table 2
Results obtained using electrode 2 (final dataset for analysis)


The results from this experiment indicate that the electrolyte content of common fruit juices, namely lime, orange, apple and mixed berry have a higher electrolyte content than typical sports drinks. The original hypothesis of this experiment was that orange juice would contain a higher electrolyte content than that of common sports drinks. The data obtained in this study supports the original hypothesis and also showed that lime, apple and mixed berry have a higher electrolyte content than the sports drinks measured here. Sports drinks are marketed as a quick way to replenish electrolytes following strenuous activities. However, results from this experiment demonstrate that fruit juices are a better source of electrolytes.

Electrode design turned out to be a key determinant of measuring conductance in a solution. The experiment was replicated with an improved electrode design in order to produce higher electric current for analysis. The improved design, using a greater electrode surface area, was critical for producing high currents in solution and for comparison of the beverages. The use of this improved design is recommended for future studies. Comparison of other popular sports drinks and other fruit juices is also recommended.

Literature Review 3

Article 1 : 

Could walking or running generate enough energy to power your cell phone or GPS device? Dr. Ville Kaajakari has developed an innovative piezoelectric generator prototype small enough to be embedded in the sole of a shoe that's designed to produce enough power to operate GPS receivers, location tags and eventually, even a cell phone.
Harnessing kinetic energy is not without its challenges because it’s difficult to generate enough energy to power today’s applications. That’s where Kaajakari's invention - which has recently been featured in the MEMS Investor Journal - comes in.
The shoe generator uses a low-cost polymer transducer with metalized surfaces for electrical contact. Traditionally, ceramic transducers are hard and therefore unsuitable to use in shoes but Kaajakari's generator is soft as well as strong so it could replace a normal heel shock absorber without loss to the user experience.
According to Kaajakari, the new voltage regulation circuits can convert the piezoelectric charge into a usable voltage and combined with the polymer transducer give a time-averaged power of two milliwatts per shoe on an average walk - that’s comparable to lithium coin/button cells and enough to power running sensors, RF transponders and GPS receivers.
"This technology could benefit, for example, hikers that need emergency location devices or beacons," said Kaajakari. "For more general use, you can use it to power portable devices without wasteful batteries. Ultimately, we want to bring up the power levels up to a point where we could, in addition to sensors, charge or power other portable devices such as cell phones."
It will be interesting to see if Kaajakari’s inventiveness pays off – will shoes of the future be capable of charging mobile devices, and at the same time will our footsteps power the buildings we walk through?

Article 2 :

Researchers have for many years attempted to harvest energy from our everyday movements to allow us to trickle charge electronic devices while we are walking without the need for expensive and cumbersome gadgets such as solar panels or hand-cranked chargers. Lightweight devices are limited in the voltage that they can produce from our low-frequency movements to a few millivolts. However, this is not sufficient to drive electrons through a semiconductor diode so that a direct current can be tapped off and used to charge a device, even a low-power medical implant, for instance.
Now, Jiayang Song and Kean Aw of The University of Auckland, New Zealand, have built an energy harvester that consists of a snake-shapes strip of silicone, polydimethylsiloxane, this acts as a flexible cantilever that bends back and forth with body movements. The cantilever is attached to a conducting metal coil with a strong neodymium, NdFeB, magnet inside, all enclosed in a polymer casing. When a conductor moves through a magnetic field a current is induced in the conductor. This has been the basis of electrical generation in power stations, dynamos and other such systems since the discovery of the effect in the nineteenth century. Using a powerful magnet and a conducting coil with lots of turns means a higher voltage can be produced.
In order to extract the electricity generated, there is a need to include special circuitry that takes only the positive voltage and passes it along to a rechargeable battery. In previous work, this circuitry includes a rectifying diode that allows current to flow in one positive direction only and blocks the reverse, negative, current. Unfortunately, the development of kinetic chargers has been stymied by current diode technology that requires a voltage of around 200 millivolts to drive a current.
Song and Aw have now side-stepped this obstacle by using a tiny electrical transformer and a capacitor, which acts like a microelectronic battery. Their charger weighing just a few grams oscillates, wiggling the coil back and forth through the neodymium magnetic field and produces 40 millivolts. The transformer captures this voltage and stores up the charge in the capacitor in fractions of a second. Once the capacitor is full it discharges sending a positive pulse to the rechargeable battery, thus acting as its own rectifier.
The team concedes that this is just the first step towards a viable trickle charger that could be used to keep medical devices, monitors and sensors trickle charged while a person goes about their normal lives without the need for access to a power supply. The system might be even more useful if it were embedded in an implanted medical device to prolong battery life without the need for repeated surgical intervention to replace a discharged battery. This could be a boon for children requiring a future generation of implanted, electronic diagnostic and therapeutic units.

Friday, 4 July 2014

Group Research Proposal

Group Project Proposal (Engineering)
Class: S2-01_______
Group Reference: A
1.    Indicate the type of research that you are adopting:

[    ] Test a hypothesis: Hypothesis-driven research
e.g. Investigation of the anti-bacteria effect of chrysanthemum

[    ] Measure a value: Experimental research (I)
e.g. Determination of the mass of Jupiter using planetary photography

[    ] Measure a function or relationship: Experimental research (II)
e.g. Investigation of the effect of temperature on the growth of crystals

[    ] Construct a model: Theoretical sciences and applied mathematics
e.g. Modeling of the cooling curve of naphthalene 

[    ] Observational and exploratory research
e.g. Investigation of the soil quality in School of Science and Technology, Singapore  

[  X  ] Improve a product or process: Industrial and applied research
e.g. Development of a kinetic phone charger for shoes 

2.    Write a research proposal of your interested topic in the following format:

Title: Development of a kinetic phone charger for shoes 

A.    Problem being addressed

Over the past few years the amount of people using smartphones in Singapore have increased.In 2013 Singapore was ranked the top 4 country for smartphone market penetration.(as stated by : the Link) From there we can also see that 71.7% of the people in Singapore uses smartphones. Singaporeans tend to use their phones while on the move.(supported by : the Link) An example from the link is that 74% of people say they use mobile web when they are “outside”. Take note that the link shows that the people use mobile web and not normal usage.

As most smartphones rely on 3G connection, it can be inferred that they will use 3G to access mobile web.This can lead to a faster draining of phone battery as 3G uses up battery faster. “2G (original GSM) was deliberately designed to be very power-efficient only for low-data rate voice services. 3G was designed to be more spectrally efficient and to deliver higher-rate data services, but at the expense of using more power. 4G offers far faster data rates and is more spectrally efficient, but draws even more power.”As quoted from the following site it proves that 3G drains a lot of the smartphone’s power.

When they are outside they cannot usually find a socket to charge their phones so they will have to rely on a portable charger when their phones are running low on battery. So people starts buying power banks to solve this problem. According to the findings of the survey we conducted in school 82% of the people who owns a portable charger said that they do use their portable charger once a day. This shows that people are using portable chargers to be able to use mobile web/3G while on the go.So our product will solve the following problems : 
  1. People’s phones running out of batteries when they are outside
  2. Power banks not being powerful enough to charge the phone multiple times.
  3. Encouraging people especially office workers to take detours when they are free so that they will be more healthier when they go to work.
  4. Encouraging people to go green as with our charger they would not need to use the socket to charge their phones.    
B.    Goals 

To develop a phone charger that is convenient to carry around,small,light and powerful

Because as the charger is attached to the shoes,the user does not need to use up the space in pockets or bags hence making it easy to carry around.By having a small and light charger people would not have problem walking around with it on their way to work.It is powerful because you can recharge it as many times as you want as long as you are walking,thus solving problems 1 & 2.


1) 6 Piezoelectric Disc


Rated Maximum Voltage (Vp-p Square Wave) : 30 Vp-p
Capacitance : 20,000 pF ±30%
Resonant Frequency : 4,200 ±500 Hz
Resonant Impedance : ≥300 Ω

Operating Temperature : -20 to +60°C
Storage Temperature : -20 to +70°C
D ±0.1 : 27 mm
d ±0.3 : 20 mm
t ±0.02 : 0.3 mm
T ±0.1 : 052 mm
Lead Wire : 28 AWG
Lead Length (L) : 200 mm

2) 4 1N4007 Rectifier Diodes

Other 3 Alternatives ways to our project 

1) One alternative for our project is a solar power charger.The solar charger employs solar energy to supply electricity to devices or charge batteries. They are generally portable.
Solar chargers can charge lead acid or Ni-Cd battery bank up to 48 V and hundreds of ampere-hours (up to 400 Ah) capacity. For such type of solar chargers, generally intelligent charge controllers are used. A series of solar cell array plates are installed separately on roof top and can be connected to battery bank. Solar chargers today use various types of solar panels, ranging from the inefficient thin film panels with 10% efficiency or less, to the much more efficient mono crystalline panels which offer efficiencies up to 19%. The solar charger is not efficient enough as it is not reliable as there will not always be sunlight everyday and the chargers take a long time to charge even with the sunlight around. 

2) We can use potatoes in the shoe to charge the phone. Inserting zinc into potato slices in the shoes will work if we connect it the USB cable to it, since the wire is made out of copper. The zinc will be slowly eaten away by the phosphoric acid in the potato, releasing the zinc electrons to join the hydrogen ions to create hydrogen gas. Electrons in the copper wire in the cable will get to the zinc and voila! However, it is not feasible as the potato will rot and the energy that will be produced will be too low.

3)  Another alternative for our project is a bike-powered generator. Now, there are other bike-powered generators out there. The most common (and cheapest) type is known as a bottle cap generator. It's essentially a contraption that is mounted to your frame or seat-post and has a little bottle cap-like wheel that is spun by your spinning tire. They are, however, not super reliable, as it's pretty easy for the cap to become disengaged with the wheel. They also aren't particularly efficient—they typically hover around 50 percent efficiency, with some high-end models claiming as much as 70 percent. We cannot use this project as it will take quite some time to build and is much more advanced than our current project.

Final Chosen Idea and reason

Our final Idea that we chose was to make a charger by putting the piezoelectric disc in the shoe will that generate power when walking.Piezoelectricity was present ever since mid-18th century. Piezoelectricity is the electric charge that accumulates in certain solid materials (such as crystals, certain ceramics in response to applied mechanical stress. You can actually find those piezo elements in your old/ outdated earphones from the 90's. Our reason for this choice is that the materials are easily obtainable and it is more reliable in a sense that as long as you are walking there will be electricity being produced.

C.    Description in detail of method or procedures (The following are important and key items that should be included when formulating ANY AND ALL research plans.)

Equipment list:      
- Cheap/ Generic USB Power bank
- Piezoelectric Transducers (6x)
- 1N4007 Rectifier Diodes (4x)
- Hookup Wire (at least 12")
- Old Pair Of Shoes
- Contact Adhesive

Tools & Equipment:
- Digital Multimeter
- Multitool (w/ pliers)
- Rotary Tool
- 100nF Mylar Capacitor (for testing)
- Hoop & Loop Fastener (Velcro)
- LED Indicators (for testing)
- Superglue (for fixing wires)
- Smartphone Sport Strap
- 5v Switching Regulator (w/ supercap)

Alternatives: (since not all can afford them)
- PowerBank > Old phone batteries + Recycled 5v Inverter
- Peizo Transducers > A pair of old & outdated earpiece
- Rotary tool > Hot Nail (for melting plastic)
- Multitool > A pair of pliers will do

• Procedures: Detail all procedures and experimental design to be used for data collection

1)Measure the Sole of the user by taking out the sole of the shoe.

2) Trace out the sole on PVC material using a marker(Note the thickness of the PVC material must be at least 2-5mm. If your material is too thick, the piezo elements will break due to too much flexing. If your material is too thin, the piezo element won't bend at all thus converting less power.)

3)Trace out the out line of the piezo discs on the PVC material.
4)Using the compass draws a circle with a radius that is 2mm smaller than that of the piezo discs outline.

5) Drill out the smaller circles.

6)Apply quick setting contact adhesives around the edges of the holes.

7)Paste the discs over the holes ensuring that they fit the outline.
8)Repeat Steps 3-7 to obtain three holes on the PVC material.(Note the PVC material should look like this: 

9)Solder all piezo elements together in parallel.(Note Don't solder them in series because you'll need more current than voltage and those piezoelectric discs will cancel each other's power output when not actuated at the same time.)

10) (a) Build a bridge diode which should look like this : 

10) (b) This is the diagram of how the circuit should be connected : 

11)Glue foam pushers on top of the piezo discs.

12)Place the insole back into the shoe.

13)Repeat the above steps for the other shoe.

14)Walk around using the shoes for a day to see how much of the phone can be charged using it.

15)Keep checking the indicator on the charger every hour to see the amount that was charged.

16)Determine the amount of time spent walking needed to charge the power bank. 

x17)From the results we can decide if more piezo discs are needed for the shoe.

• Risk and Safety: Identify any potential risks and safety precautions to be taken.

1.    As this experiment involves drilling, take caution when using the drill so that the drill is always facing away from the body.
2.    As the experiment involves soldering, take caution so that the user will not get burnt.

• Data Analysis: Describe the procedures you will use to analyze the data/results that answer research questions or hypotheses
1.    Walk around using the shoes for a day to see how much of the phone can be charged using it
2.   Keep checking the indicator on the charger every hour to see the amount that was charged.
3.    Determine the amount of time spent walking needed to charge the power bank.
4.    From the results we can decide if more piezo discs are needed for the shoe.

D. Bibliography: List at least five (5) major references (e.g. science journal articles, books, internet sites) from your literature review. If you plan to use vertebrate animals, one of these references must be an animal care reference. Choose the APA format and use it consistently to reference the literature used in the research plan. List your entries in alphabetical order.

1. Jiayang Song, K. C. (2014, February 19). Kinetic battery chargers get a boost. ScienceDaily. Retrieved July 9, 2014, from

2. Jude, G. (2010, April 29). Piezoelectric generator creates power from shoes. Piezoelectric generator creates power from shoes. Retrieved July 9, 2014, from

3. Piash, D. (2010, July 24). New Shoe Charger Charges Cellphone With Nanogenerator System Via Kinetic Energy. The Tech Journal RSS. Retrieved July 9, 2014, from

4. PETE, D. (2011, August 31). Shoe Power? Researchers Claim Breakthrough | EarthTechling.EarthTechling. Retrieved July 14, 2014, from

5. BUCZYNSKI, B. (2012, May 31). This Is One Phone Charger You'll Want To Step On | EarthTechling. EarthTechling. Retrieved July 14, 2014, from

Thursday, 3 July 2014

Research Questions

1) Electrolyte Challenge: Orange Juice Vs. Sports Drink      -To investigate whether or not a sports drink provides more electrolytes than orange juice.

2) Water to Fuel to Water: The Fuel Cycle of the Future     -Examine water's usefulness as a renewable energy source by observing how efficient a cobalt-based catalyst can be at helping to form molecular oxygen.

3) Development of a kinetic phone charger for shoes