Lecture 8

Question 1

Definition of Transducer

Answer 1

A device that is capable of transforming one form of energy into another

Question 2

What type or energy does an ultrasound transducer convert?

Answer 2

Sound energy → electrical energy; electrical energy → sound energy

Question 3

Definition of Piezoelectric Effect

Answer 3

The conversion of acoustic pressure energy into electrical energy OR electrical energy into acoustic pressure energy. Includes direct and indirect piezoelectric effects.

Question 4

Definition of Direct Piezoelectric Effect

Answer 4

When acoustic pressure energy is applied to some materials, they will deform and create electrical energy.

Question 5

Definition of Indirect Piezoelectric Effect

Answer 5

When electrical voltage is applied to some materials, they will deform and create acoustic pressure energy.

Question 6

Synonym for Piezoelectric Material

Answer 6

Ferroelectric

Question 7

Name the 4 natural Piezoelectric materials

Answer 7

1. Quartz
2. Rochelle Salt
3. Amber
4. Tourmaline

Question 8

Name the additional 4 Piezoelectric materials for the SPI

Answer 8

1. Topaz
2. Sucrose
3. Berlinite
4. Lead Titanate

Question 9

Name the most commonly used man-made piezoelectric material

Answer 9

PZT (Lead Zirconate Titanate)

Question 10

How man-made piezoelectric materials are produced

Answer 10

1. Crystal is heated to curie point
2. Crystal is placed in a strong electrical field to align the positive & negative poles
3. Crystal is cooled, polarizing the crystal and making it piezoelectric

Question 11

Definition of Curie Point

Answer 11

The temperature in which depolarizatiom takes place