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We present an integrated sensor based on a grating interferometer (GI) for in-plane displacement measurement in microregions of large engineering structures. The system concept and design, based on a monolithic version of Czarnek's GI, is discussed in detail. The technology chain of the GI measurement head (MH), including the master fabrication and further replication by means of hot embossing, is described. The numerical analyses of the MH by means of geometric ray tracing and scalar wave propagation are provided. They allow us to determine geometrical tolerance values as well as refractive index homogeneity and nonflatness of MH working surfaces, which provide proper beam guiding. Finally the demonstrative measurement performed with a model of the sensor is presented. OCIS codes: 120.0120, 120.3180, 120.4120.

This paper presents a novel combdrive configuration of a linear magnetic microactuator. We discuss in detail the influence of the air-gap geometry on the plunger motion and give design rules to avoid pull-in behavior. This analysis results in a new configuration, which is, so far, only known for electrostatic actuators. The magnetic flux is guided over several interdigitating comb structures with moderate large gap width of 25 [micro]m instead of one single plunger, as reported for earlier designs. This results in larger forces, scaling with the number of comb fingers, until the material reaches saturation. The new configuration linearizes the characteristics and saves driving power without sacrificing fabrication stability, which would arise from small air-gap widths. Several combdrive actuators featuring one, two, and eight comb fingers were fabricated in LIGA technology, simulated, and tested. For a driving current of 40 mA, the achievable stroke is measured to increase by 800% for eight comb fingers in comparison to one finger. Alternatively, for a given stroke, a reduction of the driving current of more than 50 % is measured. [2007-0103] Index Terms--Combdrive, electromagnetic actuator, optimization, system stability.

To combine the advantages of the LIGA technology and piezoelectric materials, first prototypes of movable elastic LIGA structures have been realized on piezoelectric substrates. The structures consist of a flexible beam fixed to the piezoelectric substrate at its two ends in order to amplify the [d.sub.31]-contraction of the piezoelectric substrate. By using this flexible LIGA beam as a magnification mechanism, the small displacements of the piezoelectric substrate are amplified by more than a factor of 20, offering various possibilities of applications, especially in micro-optics. In this paper, first the fabrication process and the performance of these new prototypes of LIGA piezoelectric actuators are described in detail, demonstrating the feasibility of the new concept combining the LIGA technique and piezoelectric substrates. Subsequently, LIGA-piezoelectric actuators developed for micro-optical applications are presented. These new optical actuators are also based on an elastic beam but slightly modified in order to modulate light propagating in optical fibers. They find promising applications as micro-optical attenuators or choppers whose performance is demonstrated. Index Terms - Attenuators, choppers, microactuators, piezoelectric material, X-ray lithography.