Felix Greiner

Applications of Novel High-Aspect-Ratio Ultrathick UV Photoresist for Microelectroplating

The new acrylic photoresist named AZ 125 nXT is a serious option for low-cost high-aspect-ratio UV LIGA applications. It offers advantages compared to SU-8 like good adhesion to Si substrates, rapid processing, and easy removal after electroplating. Film thicknesses of 400, 800, and 1400 μm with an aspect ratio of 20 : 1 have been shown by the authors. The photoresists excellent electroforming behavior has been proved in an extremely acid copper electrolyte at room temperature as well as in an almost neutral nickel electrolyte at 50°C. The easy removal (wet: dimethyl sulfoxide or acetone, dry: plasma with reactive radicals) releases freestanding metal structures with aspect ratios of 13 : 1 and 16 : 1.

Combined Simulation of a Micro Permanent Magnetic Linear Contactless Displacement Sensor

The permanent magnetic linear contactless displacement (PLCD) sensor is a new type of displacement sensor operating on the magnetic inductive principle. It has many excellent properties and has already been used for many applications. In this article a Micro-PLCD sensor which can be used for microelectromechanical system (MEMS) measurements is designed and simulated with the CST EM STUDIO® software, including building a virtual model, magnetostatic calculations, low frequency calculations, steady current calculations and thermal calculations. The influence of some important parameters such as air gap dimension, working frequency, coil current and eddy currents etc. is studied in depth.

A blended-learning concept for basic lectures in electrical engineering: A practical report

In this paper we present the blended-learning concept of a basic course attended by about 1000 students of various courses of study each semester. The traditionally organized course with lecture and exercise is afflicted by different time tables and knowledge background of the students, as well as being a subject with high degree of abstraction. Adding lecture and exercise recordings, interactive animations, videos, tests and a quiz as mandatory and voluntary teaching material allows an autonomous learning process at individual speed. Evaluation results and access statics show a very good acceptance of the new elements, especially lecture recordings and weekly online-tests.