Abstract: A method of batch producing capacitive pressure sensors in which a sheet of semiconductive material is provided with an insulating layer 4 on one side thereof and a plurality of cavities 1 are formed in the semiconductive sheet by removing part of the insulating layer and part of the semiconductive sheet. Simultaneously with producing the cavities in the semiconductive sheet, at least one recess is provided, again by removing part of the insulating layer and part of the semiconductive sheet.

Abstract: The invention provides a method of producing on a substrate a diaphragm which is electrically isolated from the substrate. The method comprises obtaining a substrate (2) having a diaphragm(1) thereon which comprises a flexible central portion (1a) and a shouldered peripheral portion which supports the central portion (1a) above the substrate (2), applying a mask (6) over at least a part of the central portion (1a) and converting the unmasked portion (1b) of the diaphragm to a dielectric so as to electrically isolate the masked central portion (1a) of the diaphragm from the substrate (2).

Abstract: The invention provides a method of forming a sealed diaphragm (3) on a substrate (1) which comprises providing on the substrate (1) a sacrificial layer (2) , providing a diaphragm layer (3) over the sacrificial layer (2), providing at least one aperture (5) in the diaphragm layer (3) which is spaced from the periphery of the diaphragm layer (3), at least partially removing the sacrificial layer (2) from between the substrate (1) and the diaphragm layer (3) by way of the at least one aperture (5) and closing the at least one aperture (5).

Abstract: A method of producing filaments of sub-micron cross-sectional dimensions including the steps of obtaining a substrate having a base and a delineating layer on the base and a step in a surface of the delineating layer, providing a layer of a material from which the filament is to be formed on the surface which replicates the step in the surface, anisotropically etching the layer of filament material in the direction of the surface so as to leave a filament of the material adjacent the step, and removing the delineating layer to wholly or partially separate the filament from the substrate.

Abstract: A method of hermetically sealing an electrical feedthrough (5) in a semiconductor-on-insulator device comprising the steps of producing an electrically insulating layer (2) on a semiconductive material (1) having a first surface area, producing one or more electrodes (4) on a non-conductive substrate (3) of a second surface area which may be greater than the first surface area, with each electrode having an electrical feedthrough (5) associated therewith, placing the semiconductive layer on the substrate with the insulating layer in contact with the substrate and such that each electrical feedthrough extends beyond the edge of the semiconductive layer, and bonding the semiconductive layer to the substrate to provide an hermetic seal around the feedthrough and thus protect the integrity of the electrode associated therewith and disposed between the semiconductive layer and the substrate.

Abstract: A rotational binary output encoder comprises a housing (1) defining an enclosed space (12), a shaft (3) extending through an end wall (1b) of the housing into the space (12) and having mounted on the inner end thereof a transparent planar disc member (7) having grid means (8) on one surface thereof and reflector means (6) on the other surface thereof, the grid means (8) having alternate areas (22,23) which allow or prevent the passage of light, light transmitting means (5) and light receiving means (4a,4b) mounted in said housing so that the grid means (8) intermittently interrupts the light passing from the light transmitting means (5) to the light receiving means (4a,4b) to produce opto-digital signals, and electric circuit means (10) for providing a digital electrical output from the opto-digital signals.