What type of crystal acts as the piezoelectric element in ultrasound transducers?

What type of crystal acts as the piezoelectric element in ultrasound transducers?

• A. Piezo-electric crystal
• B. Quartz
• C. Less zirconate
• D. Barium titanate

Answer: (A)

The active element in an ultrasound transducer is a piezoelectric crystal. This material has the property that when an electric voltage is applied, it changes shape and emits mechanical vibrations—producing ultrasound. Conversely, when ultrasound waves from tissue strike the crystal, it deforms the crystal and generates an electrical signal to be processed. That dual capability—emitting and receiving sound—is what makes the crystal the essential piezoelectric element. In practice, the most common materials are piezoelectric ceramics like lead zirconate titanate (PZT) because they provide high electromechanical coupling and can be fabricated into the thin discs needed for probes. Quartz is also a piezoelectric crystal and can be used in specialized probes, but its coupling is lower, so it’s less common today. Barium titanate is another piezoelectric ceramic but is not the standard choice for modern clinical transducers. The key idea is that the element must be a piezoelectric crystal, which is exactly what the correct option describes.

The active element in an ultrasound transducer is a piezoelectric crystal. This material has the property that when an electric voltage is applied, it changes shape and emits mechanical vibrations—producing ultrasound. Conversely, when ultrasound waves from tissue strike the crystal, it deforms the crystal and generates an electrical signal to be processed. That dual capability—emitting and receiving sound—is what makes the crystal the essential piezoelectric element.

In practice, the most common materials are piezoelectric ceramics like lead zirconate titanate (PZT) because they provide high electromechanical coupling and can be fabricated into the thin discs needed for probes. Quartz is also a piezoelectric crystal and can be used in specialized probes, but its coupling is lower, so it’s less common today. Barium titanate is another piezoelectric ceramic but is not the standard choice for modern clinical transducers. The key idea is that the element must be a piezoelectric crystal, which is exactly what the correct option describes.