What is Piezoelectricity?(피에조 전기)

Piezoelectricity is the electric charge created when mechanical force is applied to certain solid materials such as crystals, some types of ceramic, DNA, bones, etc. In this text I am going to explain how piezoelectricity in crystals work.

 

Let's say that the crystal has a tetrahedron structure. In normal situations, it will have a neutral charge of 0, since all of it's dipole moments cross out each other. But when a strong enough mechanical force is applied, the crystal's structures may change, or 'squashed'. The dipole moment parallel to the direction of the force will be stronger than the squashed dipole moments that are almost perpendicular to the applied force. Therefore, the total sum of the crystal's dipole moments will be pointing to some direction; the direction in which piexoelectricity flows. The direction piezoelectricity flows depends on whether the crystal was compressed or inflated.

when a crystal is compressed or inflated, piezoelectricity flows

Pieoelectricity is used for several usages. For example, the switch of a lighter is connected to a piezoelectric material, which creates an electric spark that is used to ignite the gas. Others uses can be detecting sound waves or generating electricity. Also, piezoelectric crystals such as quartz can be used in clocks to keep the time correct.