Performance of an Ultrasonic Imaging System Based on a 45-MHz Linear PVDF Transducer Array: A Numerical Study

Table 1

Material constants used in the numerical simulations [20–23]. A PVDF film with Young’s modulus and electromechanical coupling factor of 4.0 GPa and 14%, respectively, was chosen. Properties of PVDF films vary depending on the processing technique, temperature, frequency, and age [24–26]. Attenuation in PVDF, epoxy, copper, and human skin are based on data from [23, 27–29].

			PVDF	Epoxy	Cu	Au	Skin
Density	𝜌	(10^3 kg/m^3)	1.78	1.20	8.96	19.3	1.00
Young’s modulus	𝐸	(10^9 Pa)	4.0	3.0	120	79	—
Poisson’s ratio	𝛾	(−)	0.20	0.34	0.31	0.46	—
Longitudinal wave speed	𝑉𝑙	(10^3 m/s)	1.6	2.0	4.3	4.4	1.54
Transverse wave speed	𝑉𝑡	(10^3 m/s)	1.0	1.0	2.3	1.2	0
Attenuation	𝛼	(dB/(cm MHz))	10	1.2	0.03	—	2
Piezoelectric const.	𝑒31	(C/m^2)	0.004	—	—	—	—
Piezoelectric const.	𝑒33	(C/m^2)	−0.096	—	—	—	—
Piezoelectric const.	𝑒15	(C/m^2)	0	—	—	—	—
Permittivity	𝜖^𝑆11,𝜖^𝑆33	(10^−12 F/m)	106	—	—	—	—