Towards Automated Visual Inspection and Classification of Micro-Parts
The mechanical manufacturing of micro-parts is a challenging field of research. Because of high quality requirements and small tolerances, manufacturing processes have to be very stable and precise. In order to achieve high precision a suitable quality assurance concept is required. Only measured features can be used for statistical process control (SPC). Therefore, this paper presents a concept of an automated visual inspection and classification methods for micro-parts. Using confocal laser scanning microscopy, high-resolution 3D-height maps with depth selectivity are obtained. The identification of surface imperfections is done with a set of conventional image processing techniques. Afterwards, these kinds of surface defects are classified by the use of classification methods like decision trees.
RECONSTRUCTION OF 3D DRAWINGS FOR ENGINEERING OBJECTS FROM 2D CAMERA PERSPECTIVES
Engineering industry requires line drawings for manufacturing, machining and production of engineering equipments/objects.The generation of these paper-based drawings or computerized drawings is a complex and time consuming task. Conventionally, these drawings contain three two dimensional (2D) orthographic views, namely top, front and side of an object. Modern trends in engineering industry require three dimensional (3D) engineering drawings. Therefore, to fulfill this requirement the conversion of these 2D drawings to 3D drawings is essential.This conversion is referred to as the reconstruction. Various approaches have been proposed for the conversion/reconstruction using existing drawings. 
In this thesis, we developed 3D reconstruction methodology that uses camera perspectives in the reconstruction process. Note that in the existing approaches this feature (camera perspective) is not used. Another salient feature of our approach is in its underlying mechanism of tangential lines and hypothetical cuboid. Using our proposed approach, manufacturing cost and time can be saved, and it can also be helpful in technology transfer.
Submicron polymer structures with X-ray lithography and hot embossing
This article describes the process chain for replication of submicron structures with varying aspect ratios (AR) up to 6 in polymethylmethacrylate (PMMA) by hot embossing to show the capability of the entire LIGA process to fabricate structures with these dimensions. Therefore a 4.7 μm thick layer of MicroChem 950k PMMA A11 resist was spin-coated on a 2.3 μm Ti/TiOx membrane. It was patterned with X-ray lithography at the electron storage ring ANKA (2.5 GeV and λc ≈ 0.4 nm) at a dose of 4 kJ/cm3 using a Si3N4 membrane mask with 2 μm thick gold-absorbers. The samples were developed in GG/BDG and resulted in AR of 6–14. Subsequent nickel plating at 52°C resulted in a 200 μm thick nickel tool of 100 mm diameter, which was used to replicate slit-nozzles and columns in PMMA. Closely packed submicron cavities with AR 6 in the nickel shim were filled to 60% during hot embossing.