Electrostrictive transducers rely on which effect to generate strain?

• A. Linear piezoelectric effect
• B. Quadratic electrostrictive effect
• C. Magnetic resonance
• D. Thermal expansion

Answer: (B)

Electrostrictive transducers rely on a quadratic response of the material to an electric field. The strain produced by electrostriction is proportional to the square of the applied field (S ∝ E^2). This means the deformation is the same whether the field is positive or negative, unlike a linear piezoelectric effect where strain follows the field direction (S ∝ E). The coupling arises from how the material’s polarization interacts with the lattice, often described by S ∝ P^2 or S ∝ E^2 through an electrostrictive coefficient. This quadratic relationship is the defining feature that enables electrostrictive transduction. Magnetic resonance doesn’t generate such direct electromechanical strain, and thermal expansion would come from heating rather than a field-induced lattice change.