Table 1.

The thickness and mechanical properties of each material layer of the film.

Material	Copper (Cu)	Nickel (Ni)	PZT	Silver (Ag)
$\mathrm{Thickness} \left(\mathsf{\mu }\mathrm{m}\right)$	100	10	158	10
Young’s modules (GPa)	128	200	67	83
Density (kg/m3)	8960	8908	7800	10,490
Poisson’s ratio	0.34	0.31	0.39	0.37
Piezoelectric constant (pm/V)	N/a	N/a	−210	N/a