Abstract: The present invention provides a vibration detector device (1) suitable for use as a cochlear implant (12). The detector device (1) comprises a substrate (2) formed and arranged for supporting a plurality of resonator bars (4). The resonator bars (4) are of a uniform length and are supported at each end (6, 8) by the substrate material (2). Each of the resonator bars (4) has a distinct resonant frequency characteristic and is arranged with a piezoelectric generator to generate a signal in response to receiving a vibration which causes the resonator bar (4) to vibrate at its resonant frequency.

Abstract: An X-ray interferometer comprises a plane film of material of low X-ray absorption coefficient, a first surface facing one side of the film, and a second surface facing the other side of the film and substantially opposite the first surface, the first and second surfaces being of high X-ray absorption coefficient and being relatively inclined at a small angle, arranged so that when a beam of X-rays is incident on the film at a glancing angle in the plane in which the small angle of relative inclination lies, a first part of the incident beam is, in sequence, transmitted by the film, reflected by the first surface, and reflected by the film as a first partial beam, and a second part of the incident beam is, in sequence, reflected by the film, reflected by the second surface, and transmitted by the film as a second partial beam which intersects the first partial beam.

Abstract: An x-ray diffraction grating consisting of a structure having a surface capable of reflecting x-rays, said surface being grooved so that in cross-section the profile of said surface alternates regularly between geometrically similar lines, in which the height of the alternation varies significantly over the area of the surface. The grating may be plane or curved; the variation in height may occur as a single step, a plurality of steps or may be continuous; the variation may occur either transverse to or parallel to the grooving.