Table 2.

Physical quantities and experimental parameters

Parameters	Descriptions	Units
AC	Alternative current	Volt
IDTs	Interdigital transducer	mm
f	Frequency	Hz
C	Speed of sound	m/s
C1	Acoustic wave velocity in fluid	m/s
Cs	Acoustic velocity in piezoelectric substrate	m/s
λ	Wavelength	m
Zp	Acoustic impedance of particle	Pa·s/m3
Zm	Acoustic impedance of surrounding medium	Pa·s/m3
Ktr	Dimensionless coefficient	-
Rp	Radius of the particle	nm
Rb	Bubble radius	nm
FPRF	Pulse reputation force	Newton
k	Wave number	1/m
ρl	Density of surrounding fluid	kg/m3
ρp	Density of particle	kg/m3
Fa	Axial force on particle	Newton
Fd	Stokes force	Newton
ϕ	Acoustic contrast factor	dB
P0	Acoustic pressure amplitude	Pa
x	Axial distance of the particle from the pressure node	m
Vp	Particle volume	m3
v	Relative velocity between the fluid and the particle	-
u	Fluid viscosity	m/s
βp	Particle compressibility	GPa/m3
βl	Fluid compressibility	GPa/m3
θR	Rayleigh angle	-
FSRF	Surface radiation force	Newton
d	Distance between particles	m
ω	Angular frequency	Rad/s
Ab	Amplitude of bubble oscillation	m