Méthode de libération d'une pièce micromécanique et pièce micromécanique comprenant des attaches sacrificielles

A method for fabricating a micromechanical part from a substrate in which the part is fabricated by providing a plurality of fasteners between the part and the substrate, the fasteners being sacrificial, characterized in that the fasteners include at least one hinge at the end of each fastener located beside the part, and in that the method includes a step of breaking the sacrificial fasteners. The micromechanical parts employing this type of sacrificial fastener are also described

Large angle flexure pivot development for future science payloads for space applications

An innovative design of a Large Angle Flexure Pivot (LAFP) is described. It combines the advantages of flexure mechanisms while surpassing one of their few flaws, small displacement strokes. The LAFP design exceeds these angular limitations to reach a deflection of 180° (±90°). The centre shifts laterally by less than ±35 μm throughout the full rotation range. The LAFP is meant to be mounted in pairs, coaxially and with the payload between them. The intended application of the LAFP is to angularly guide an optical component in a space environment for future science missions operating in a cryogenic environment. A dedicated performance test bench was developed and manufactured to test the pivot characteristics notably the lateral shift using Eddy current sensors. The test bench incorporates a representative dummy payload for mass and inertia. Extensive FEM analysis has been performed to validate the design at component level and further analysis with the pivots mounted with a representative payload on a test bench for random vibration, shock and thermal cycling environment. The second test bench for the vibration and shock tests has been manufactured incorporating a simplified launch locking device. The performance tests have confirmed a lateral shift of less than ±35 μm over an angular range of ±90°. The pivots have been successfully tested and survived vibration loads for high level sine at 24 g and random vibration at 12 grms in all three directions