There is provided a piezoelectric device comprising a first electrode, a piezoelectric layer that is formed above the first electrode, a second electrode that is formed above the piezoelectric layer and a coating layer that is formed above the second electrode consisting of tungsten or titanium. These beams, as well as the tapered portion and a handle, are constructed from a composite material, such as fiber reinforced plastic. 9 wt % monomer defined by the formula:wherein: R is an aliphatic group of 1 to 10 carbons;R1 is an aliphatic group of 1 to 10 carbons;R2 is an alkyl, alkyl ether, aryl ether, silane or silicone; andwherein R and R1, R and R2 or R1 and R2 may be taken together to form a cyclic alkyl or aryl group;0. In another aspect of the invention, an implant includes a spacer and separate extensions engageable with the spacer. The brightness of the plasma is increased compared with sources which collect radiation emerging transversely from the plasma. Process for manufacturing such multilayer structure, which comprises co-extruding or co-blowmolding polymer compositions and so as to obtain one couple of adjacent layers and.