Abstract: The present invention provides a method for producing a composite material comprising an array of piezoelectric fibres, the method comprising: (a) providing: (a1) a plurality of first strips comprising a piezoelectric material or a precursor to a piezoelectric material, and a first carrier, and (a2) a plurality of second strips comprising a decomposable material, and a second carrier; (b) placing said pluralities of said first and second strips alternately on top of one another to form a stack in which at least a portion of said first strips is separated from adjacent first strips by a second strip; (c) a heating step comprising heating said stack to remove said first and second carriers and said decomposable material; (d) impregnating said stack with a filler material to form a composite stack of piezoelectric strips; and (e) cutting said stack to form a composite material comprising an array of piezoelectric fibres. In an alternative method the cutting (e) is performed before the heating step (c).

Abstract: A coating device for use in coating circular cross-sectioned substrates has a semi-circular doctor blade. The coater may also have a plate for holding axially symmetric substrates which can be rotated about an axis. A groove in the plate centers the substrate on the plate for rotation. The doctor blade is located adjacent to the substrate such that when the plate and substrate are rotated, the doctor blade applies a uniform thickness of coating to one side of the substrate. After one side of the substrate has been coated, the other side is coated by placing the substrate coated side down on a plate with a larger groove to accommodate the increased size of the substrate due to coating.