Etching techniques, distributed elements

An array of backing electrodes, realized by photolithography and chemical etching techniques, can be bonded on a polymeric subs te and can lodge a ferroelectric polymer film onto which a front electrode has been previously coaled. PVDF or copolymer films can be poled locally through such electrodes, but also a film poled ova its whole surface may be used without affecting the distribution of the acoustic field or the cross-talk between adjacent elements. 

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