Membrane, especially for an optical device having a deformable membrane

Method of producing an optical device with deformable membrane in which:

• on an initial substrate, a first sacrificial mould is formed,
• a deformable film of the membrane is deposited on the first sacrificial mould so that a peripheral anchoring zone of the film is anchored on the support,
• at least one conductive path is formed which runs on the film intended to supply with energy at least one conductive movable part formed later of electrostatic actuating means,
• a second sacrificial mould is formed for the movable part of the electrostatic actuating means, this second sacrificial mould extending on the film and on the initial substrate, the movable part that has to have a foot fastened to the film of the membrane in an intermediate zone situated between the anchoring zone and a central zone,
• the movable part is deposited on the second sacrificial mould,
• the second sacrificial mould is eliminated so as to free one leg of the movable part having a free end and one end connected to the foot,
• the movable part and the film are protected with a protection device transferred onto the initial substrate,
• a fixed electrode facing the movable part is formed,
• the first sacrificial mould is eliminated by means of an access through the initial substrate or the membrane,
• a liquid is trapped between the film and the protection device or in the place of the first sacrificial mould.