Linked Micro Parts Referencing System

For simplified processing, micro parts are handled as linked parts. The length of the frame structure of these linked parts can change during a multi-stage production process especially when forming is included. Hence, the positions of individual parts are not constant within the linkage. An individual referencing of the parts becomes necessary in each production step. In this paper, a visual high-speed on-line part referencing system is presented and analyzed. Especially, the trade-off between the highest possible feed velocity and the demand of high accuracy in micro production is taken into account. In addition to this general characterization application related testing with stepwise positioning is performed.

Coupling System for Ultra Precision Machining

The mass production of plastic parts containing micro structures in optical quality requires molds with corresponding surface quality. These micro structured molds can be produced by UPC （ultra precision cutting）. To produce a high surface quality the ultra precision machine spindles must be well balanced. It is not sufficient to balance the tools and the spindle separately. They have to be balanced while assembled to ensure the required balance quality grade better than G0.4. One possibility to decrease setup times and increase the quality of the spindle balancing is to enhance the unbalance induced vibrations and thus allowing better unbalance detection. In this paper a coupling system between the spindle and machine frame based on flexure joints is presented. The experimental setup provides two states： operational and setup. The operational state provides a high stiffness, whereas the setup state allows the spindle to vibrate along one degree of freedom, enhancing the vibrations created by the unbalance. The system is analyzed concerning its ability to restore the defined conditions in the operational state as well as its capability to enhance the detection of unbalances in the setup state.

Uncertainty and Resolution of Speckle Photography on Micro Samples

The efficient development of new materials with defined properties requires fast methods of testing low volumes of material,such as a high-throughput investigation of spherical metallic micro samples with varying compositions and structuring treatments.A classical material testing method for macro samples,the tensile test cannot be employed for analyzing the mechanical properties of spherical samples with diameters below 1 mm since there are currently no methods for holding and stretching them.A combination between the incremental electrohydraulic extrusion as stress actuation unit and the speckle photography as strain measuring method is presented for obtaining the required mechanical characteristics.Positive longitudinal strain is generated at stepwise extrusion through<1 mm wide forming channels using a liquid punch and the deformation is observed in situ after each forming step at the interface between the micro sample and a transparent window integrated into the forming die.The occurring local strain fields with a lateral extension down to 100 pm and high gradients require displacement measurements with high lateral resolution over a large range of local dislocations between 0.1 and>10 μm.It is unknown,whether the speckle strain measuring method is able to provide the necessary low uncertainty for the required resolution in the whole measuring range.Therefore,theoretical and experimental investigations of the deformation measurability using the speckle correlation method are presented,showing that local displacements up to 10 μm can be measured with a spatial resolution between 3 and 10μm depending on the displacement size.The dominant effect influencing the measurement uncertainty for displacements at this high spatial resolution is the speckle noise,resulting into measurement uncertainties of less than 100 μm.Hence,speckle photography is shown to be applicable for tensile test on micro samples.