In reverse piezoelectric operation, what is the sequence after the crystal oscillates?

In reverse piezoelectric operation, what is the sequence after the crystal oscillates?

• A. crystal emits heat directly
• B. crystal vibrates -> sound waves -> vibrate tissues -> friction -> heat (voltage passes through crystal)
• C. crystal creates magnetic field
• D. crystal stops vibrating after one cycle

Answer: (B)

When a piezoelectric crystal is driven by an electrical signal, it converts electrical energy into mechanical energy, causing the crystal to vibrate and emit ultrasonic waves. Those sound waves travel into the body and make the tissues vibrate as the energy is transmitted through them. As the acoustic energy is absorbed by tissue, it is transformed into heat by friction and viscous losses within the tissue. The electrical drive continues to pass through the crystal while it vibrates, sustaining the output. This sequence—vibration producing sound waves, waves interacting with tissue to cause heating—fits the mechanism of reverse piezoelectric operation. The other options don’t describe how ultrasound transducers work: heating isn’t direct from the crystal itself, a magnetic field isn’t the primary effect, and the crystal doesn’t stop vibrating after just one cycle as long as the drive persists.

When a piezoelectric crystal is driven by an electrical signal, it converts electrical energy into mechanical energy, causing the crystal to vibrate and emit ultrasonic waves. Those sound waves travel into the body and make the tissues vibrate as the energy is transmitted through them. As the acoustic energy is absorbed by tissue, it is transformed into heat by friction and viscous losses within the tissue. The electrical drive continues to pass through the crystal while it vibrates, sustaining the output. This sequence—vibration producing sound waves, waves interacting with tissue to cause heating—fits the mechanism of reverse piezoelectric operation. The other options don’t describe how ultrasound transducers work: heating isn’t direct from the crystal itself, a magnetic field isn’t the primary effect, and the crystal doesn’t stop vibrating after just one cycle as long as the drive persists.