Piezoelectric Constant

The piezoelctric constant implies the coupling of electric and mechanical fields in a group of crystalline materials and polymers. It is defined by the following relationship.

where ε = strain,  s = compliance modulus, σ = applied stress and E is the electric field which is also expressed as
E = V/t, V = applied voltage, t = thickness of the medium across which the voltage is applied

The piezoelectric constant plays an important role in selecting so called 'smart material' for sensor and actuator integrated structures. The following are the piezoelectricconstant of some of the mostly used materials