frequency response of piezoelectric transducer

piezoelectric acoustic sensor

piezoelectric plate energy harvesting

piezoelectric plate bimorph

The piezoelectric acoustic sensor is used to control the suspended particles in the fluid, which mainly uses the pressure difference between the particles to drive the particles to move to the minimum,its pressure point is to achieve the role of particle. The piezoelectric plate energy harvesting are acting on the particles in the standing wave sound field are demonstrated: the main axial is acoustic radiation force, the main ultrasound is acoustic radiation force and the secondary acoustic radiation force.

 The main axial acoustic radiation force is generated by the interaction of a single particle and an acoustic wave. The secondary acoustic 40khz piezoelectric plate transducer is derived from the interaction of two particles in the sound field. The direction of the main transverse acoustic radiation force is perpendicular to the acoustic wave propagation direction in these three kinds of acoustic radiation forces, the secondary acoustic radiation force is several orders of magnitude smaller than the primary axial acoustic radiation force, and the principal axial acoustic radiation force usually plays the largest role under the action of the acoustic radiation force, the particles in the standing wave field will converge toward the antinodes of the acoustic pressure wave, that is, the minimum pressure point. 

Whether the piezoelectric plate sensorare clustered at the nodes or at the antinodes depends on whether the density and the compressibility of the particles.which are higher or lower than the fluid medium they carry. In the standing wave field. Particles are clustered at the nodes or antinodes of the sound pressure, so changing the frequency of piezoelectric acoustic sensor can change the wavelength, which can change the location of the particles, so that the particles can be transported by continuously changing the frequency. The separation effect of the standing wave on the particles is due to the difference in the acoustic radiation force of different particles in the sound field. Using the principle of traveling wave the traveling wave can be excited on the surface of the elastic material, and the trajectory of the point on the surface can be rendered as an ellipse. The piezoelectric plate bimorphis in the traveling wave field move under the action of the friction force, and the direction and the line of movement wave is with the pressure difference generated in the fluid by the traveling wave sound field, the pumping of the fluid can be achieved. In the operation of sound waves on particles, the stationary wave field has a significant effect on the enrichment of particles, while the traveling wave field has advantages in the transmission of particles and fluids.