Abstract: The application describes improvements to (MEMS) transducers (100) having a flexible membrane (301) with a membrane electrode (302), especially where the membrane is crystalline or polycrystalline and the membrane electrode is metal or a metal alloy. Such transducers may typically include a back-plate having at least one back-plate layer (304) coupled to a back-plate electrode (303), with a plurality of holes (314) in the back-plate electrode corresponding to a plurality back-plate holes (312) through the back-plate. In embodiments of the invention the membrane electrode has at least one opening (313) in the membrane electrode wherein, at least part of the area of the opening corresponds to the area of at least one back-plate hole, in a direction normal to the membrane, and there is no hole in the flexible membrane at said opening in the membrane electrode. There may be a plurality of such openings. The openings effectively allow a reduction in the amount of membrane electrode material, e.g.

Abstract: The application describes improvements to (MEMS) transducers (100) having a flexible membrane (301) with a membrane electrode (302), especially where the membrane is crystalline or polycrystalline and the membrane electrode is metal or a metal alloy. Such transducers may typically include a back-plate having at least one back-plate layer (304) coupled to a back-plate electrode (303), with a plurality of holes (314) in the back-plate electrode corresponding to a plurality back-plate holes (312) through the back-plate. In embodiments of the invention the membrane electrode has at least one opening (313) in the membrane electrode wherein, at least part of the area of the opening corresponds to the area of at least one back-plate hole, in a direction normal to the membrane, and there is no hole in the flexible membrane at said opening in the membrane electrode. There may be a plurality of such openings. The openings effectively allow a reduction in the amount of membrane electrode material, e.g.

Abstract: The application describes improvements to (MEMS) transducers (100) having a flexible membrane (301) with a membrane electrode (302), especially where the membrane is crystalline or polycrystalline and the membrane electrode is metal or a metal alloy. Such transducers may typically include a back-plate having at least one back-plate layer (304) coupled to a back-plate electrode (303), with a plurality of holes (314) in the back-plate electrode corresponding to a plurality back-plate holes (312) through the back-plate. In embodiments of the invention the membrane electrode has at least one opening (313) in the membrane electrode wherein, at least part of the area of the opening corresponds to the area of at least one back-plate hole, in a direction normal to the membrane, and there is no hole in the flexible membrane at said opening in the membrane electrode. There may be a plurality of such openings. The openings effectively allow a reduction in the amount of membrane electrode material, e.g.