When an electrical signal is applied to a piezoelectric element, what happens to the element?

When an electrical signal is applied to a piezoelectric element, what happens to the element?

• A. It expands and contracts
• B. It undergoes temperature fluctuations
• C. It produces an electrical signal of the opposite polarity
• D. It emits electromagnetic radiation

Answer: (A)

Applying an electric field to a piezoelectric element causes mechanical deformation—the converse piezoelectric effect—so it expands and contracts. The electric field interacts with the crystal lattice and produces strain along the material’s polarization axis, changing its dimensions in response to the applied voltage. This is the fundamental way piezoelectric devices act as actuators. Temperature changes or EM radiation aren’t the defining responses you should expect from simply applying a voltage. Any slight heating would be incidental from current flow, and emitting electromagnetic radiation isn’t a typical result of driving a piezoelectric element. The key takeaway is that the applied electrical signal directly translates into a physical change in size.

Applying an electric field to a piezoelectric element causes mechanical deformation—the converse piezoelectric effect—so it expands and contracts. The electric field interacts with the crystal lattice and produces strain along the material’s polarization axis, changing its dimensions in response to the applied voltage. This is the fundamental way piezoelectric devices act as actuators.

Temperature changes or EM radiation aren’t the defining responses you should expect from simply applying a voltage. Any slight heating would be incidental from current flow, and emitting electromagnetic radiation isn’t a typical result of driving a piezoelectric element. The key takeaway is that the applied electrical signal directly translates into a physical change in size.