Piezoelectricity G.R.O.W Project

Ben Iverson and Chloé

Mihalcheon

Our Questions...

❖ Why are some minerals piezoelectric, while others are

not?

❖ What are the everyday applications of piezoelectricity?

What is piezoelectricity?

❖ When certain minerals are exposed to a short burst of

high stress, they can produce a temporary electric

charge. This is called piezoelectricity. The Greek word

"piezo" means "push" or "squeeze" so, piezoelectricity

literally means electricity derived from pushing. Any

mineral with this property is referred to as a piezoelectric

crystal (or p.c for short).

How does piezoelectricity work?

❖ Imagine the p.c as a battery, with a positively charged

end and negatively charged end. In a resting state, these

charges cannot be noticed. However, if the crystal is

compacted, current can flow, and the charged is

released.

❖ These positive and negative charges are normally

balanced out, so you can't noticed then. Any compaction

(or stretching) of the crystal can mess up the balance,

resulting in a shock.

What materials are piezoelectric?

❖ Many materials, both natural and

synthetic are piezoelectric,

including:

- Quartz

-Sucrose (sugar)

-Tendon & bone

-Dentin & enamel

-Silk

-DNA

Why are some materials piezoelectric, while others are not?

❖ It all has to do with the mineral's structure. A mineral with

a symmetrical structure will not be piezoelectric because

the electrical charges are always balanced. If the mineral

structure is not symmetrical, it can be deforming,

resulting in electric charge flowing through the crystal, so

this mineral is piezoelectric.

Applications

❖ Use of piezoelectricity can be found in:

❖ Quartz watches, piezoelectric

crystals are inside to help keep time

❖ Microphones, used to translate

sound energy into electrical signals

❖ Record players, p.c are used to

"read" the record

❖ Cigarette/barbecue lighters, used to

spark the gases to light the flame

❖ Igniters of many grills and cook tops

Piezoelectricity in Lighters

❖ Barbecue lighters use naturally

occurring quartz as the igniter

because it is piezoelectric .

When you pull the trigger on a

lighter, that clicking noise you

hear is actually the crystal being

compacted. The spark is

creates ignites the gas to light

the flame.

Piezoelectricity in Action

The G.R.O.W Process

Our Topics

❖ Our initial question involved finding

out what minerals are in the

superfruits that are supposed to

make drinks like Bai5 so healthy.

❖ We then moved on to what minerals

are present in our iPhones.

❖ Our topic changed once again to

piezoelectric minerals and what they

are.

❖ Half-way through our research, we

expanded our question to include

applications of piezoelectricity.

Obstacles faced

❖ We initially faced many obstacles, which is why we

switched our topic so many times. These first few obstacles

included other people researching similar topics and lack of

readily available information. We realized that it would be

better to switch to a new topic that has a lot of information

and that other people are not researching.

❖ While researching our final topic, we still had a few issues

with lack of available information. To fix this, we would

broaden the range of our question so that we had more

resources to our disposal.