We don’t think we can generate more electricity than a quartz with synthetic crystals. This is because most electronics are powered by quartz and not synthetic crystals, and we think scientists have already found out why not to use synthetic crystals. 

Both calories and electricity are forms of energy, so the crystal with the most calories would generate the most electricity. Out of the the synthetic crystals, that would be sugar.

What is Piezoelectricity?

Piezoelectricity is an ability certain things have, causing it to generate electricity when we apply mechanical stress (pressing or squeezing it).

What is Electricity, Voltage, and a Voltmeter?

Electricity is energy made when electrons, which have negative charge, move. 

Volts are a unit used to measure how strong an electric current is. For our experiment, we will use millivolts, 1,000 millivolts being 1 volt.

A voltmeter measures how many volts something is producing (their voltage).

What is a Crystal?

A crystal is a solid which its atoms or molecules are put together in a specific pattern. They can be made by humans or nature in many different ways. For our experiment, we will be growing crystals from a supersaturated solution. In our supersaturated solution, the atoms or molecules of the solute are taken part and rearranged in a specific pattern and the crystals form. 

Calories and Chemical Formula of our Materials

Variables

Growing Crystals

Manipulated: Types of Solute

Responding: Type of Crystal that Grew

Controlled: Room Temperature, Air pressure, amount of solute, amount of solvent, time, type of cup, humidity 

Measuring Voltage

Manipulated: Types of Crystal

Responding: Voltage generated

Controlled: Room Temperature, Air pressure, person applying force, Voltmeter used, time, humidity, number of trials, how force was applied

Control: Quartz

Procedure 

1. Make crystals
   1. Heat 1 cup of sugar with 2/3 cup of water in a pan
   2. Bring the water to a boil while stirring with a popsicle stick, until the solution become supersaturated
   3. Suspend a pipe cleaner into a cup, making sure the pipe cleaner doesn’t touch the sides of the cup
   4. Cover the top with a paper towel, and grow them for 8 days 
   5. Repeat the steps above with salt, epsom salt, and baking soda instead of sugar
   6. Record observations in Table 1 and take pictures of the crystals
2. Measure voltage of crystals
   1. Apply mechanical stress to the crystals with a wooden dowel (salt, sugar, baking soda, epsom salt, and quartz) using a similar force 4 times each
   2. Record observations in Table 2 (low power) and Table 3 (high power)

Observations - Growth of the Crystals

Table 2 - Voltage Of Crystals (mV) - Low Power

Table 3 - Voltage Of Crystals (mV) - High Power

Factors that Affect Crystal Production

Solubility

We assumed all solutes have the same solubility. As it turns out, different substances have different solubilities. None of the were at the supersaturation point, but epsom salt was closest to the supersaturation point, so that is why it grew best.

Contamination 

As we know, burning plastic releases pollutants into our atmosphere. When we directly poured hot water into our plastic cup, it probably melted the plastic, which caused there to be pollutants and other chemicals to be released. These pollutants and chemicals might worsen crystal growth.

Ion Valence 

If something has more ion valence, it will have better crystal production. Epsom salt has an ion valence strength 2 (Mg²⁺, SO₄^2-), salt has an ion valence of 1 (Na⁺, Cl^-). An ion valence strength of 2 is expected to make more crystals than something with an ion valence of 1.

Factors affecting Piezoelectricity

Mechanical stress applied - More stress, more electricity

• From graph one, high power has more electricity

Surface area - Less surface area, more electricity 

• Quartz 1 and Quartz 3, about the same height, Quartz 1 less surface area, Quartz 1 more electricity, salt crystal was smaller surface area than epsom salt crystal, about the same height, more electricity at low power

Height - More height, more electricity 

• Quartz 1 and Quartz 2 about the same surface area, different height, Quartz 1 more electricity

Synthetic vs. Quartz

It is possible for synthetic crystals to generate more electricity than a quartz, and you can see this on the graph. 

Both synthetic crystals and quartz did not seem to run out of electricity, and kept producing electricity after four tries. 

The synthetic crystals shattered at high power, while the quartz did not, as you can also see on the graph. Since quartz were made under extreme heat (igneous rock), pressure (sedimentary rock), or both (metamorphic rock), it became a very hard rock. Our synthetic crystals, on the other hand, were made at room temperature and basically no pressure (air pressure), making them very brittle.

From our experiment, materials did not seem to matter, the amount of mechanical stress and shape of the crystals did. By changing these factors, we can generate more electricity than a quartz (as long as the synthetic crystals do not shatter).

Our hypothesis was incorrect, and the electricity produced does not seem to relate to the amount of calories something has, based on our experiment.

The electricity produced relates to how thick a crystal is, its surface area, and the amount of mechanical stress applied. A crystal can produce more electricity if it is thick, has a small surface area, and can withstand lots of mechanical stress. By changing these attributes, synthetic crystals can produce more electricity than a quartz, like seen in our low power experiment. Compared to our synthetic crystals, quartz produced more electricity at high power, as it could withstand more mechanical stress producing more electricity.

Using crystals for energy is environmentally friendly and renewable, as the crystals do not seem to run out of energy. If scientists were to research this topic more and gain a better understanding of it, we think it could be used as a main energy source in the future!

• Solubility of materials, same ratio for all ingredients, some solutions were over the supersaturated (baking soda) some weren’t saturated enough (sugar)
• 1 cup of different solutes to be different in weight
• Hot water poured straight into plastic cup, releases contaminates into solution
• High power shattered our man-made crystals
• Our fingers produced static electricity that was affected the readings (we solved this by using a wooden dowel)
• Our mechanical stress will vary (did experiment 4 times to reduce problem)
• Rock was not smooth, was hard to press

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We would like to acknowledge anyone who has helped us in this project. This includes our parents, Mr. Hagen, and the person lended us the voltmeter.