Backing material is also called the _______.

Backing material is also called the _______.

• A. Damping Element
• B. Matching Layer
• C. Gel
• D. PZT

Answer: (A)

The backing material’s job is to damp the piezoelectric element’s vibrations. By absorbing energy that would keep the crystal ringing after it’s driven, the backing shortens the emitted pulse and broadens the transducer’s bandwidth. That damping action is why this layer is called the damping element. The other items have different roles: the matching layer sits on the front face to improve acoustic impedance match to tissue; the gel is the coupling medium between the transducer and the skin; and PZT is the piezoelectric ceramic that actually converts electrical energy to sound (and vice versa).

The backing material’s job is to damp the piezoelectric element’s vibrations. By absorbing energy that would keep the crystal ringing after it’s driven, the backing shortens the emitted pulse and broadens the transducer’s bandwidth. That damping action is why this layer is called the damping element. The other items have different roles: the matching layer sits on the front face to improve acoustic impedance match to tissue; the gel is the coupling medium between the transducer and the skin; and PZT is the piezoelectric ceramic that actually converts electrical energy to sound (and vice versa).