P2I-7 1-3 Piezofiber-Silicone Rubber-Composite with Different Resonance Frequencies Enabling Frequency Controlled Shapes of the Ultrasound Radiation Pattern

Arranging piezofibers (PZT) with different clearly separated resonance frequencies in a 1-3 connectivity composite with a soft filling material like silicone rubber that mechanically decouples the piezofibers and driving all piezofibers in parallel with signals of variable frequencies, mainly piezofibers with that resonance frequency vibrate that matches the driving frequency. The piezofibers with different resonance frequencies are arranged corresponding to the wanted controllable radiation patterns. A simple theoretical model to define the vibration behaviour of 1-3 piezofiber - silicone rubber - composites (PFSRC´s) that shows good agreement with the measured results is presented.