Design criteria and manufacturing technology of piezo-polymer transducer arrays for acoustic guided waves detection

Composite laminates are widely used in space industry and are generally tested for failures with acoustic guided waves. This work shows that piezo-polymer material such as PVDF offer a possibility to design comb or interdigital transducers (IDT) in a versatile way by the electrodes pattern definition with a laser ablation process of metallized films. A transducer arrays design process is described and manufacturing of prototypes is illustrated. Predicted responses of the selected modes of propagation by computer simulations are in good agreement with the theoretical ones. Finally the characteristics of IDT transducers working at central frequency of about 0.5 MHz on FR-4 glass-epoxy, 0/spl deg/-90/spl deg/ composite laminates, are reported.