1. Institut für Mikroelektronik Stuttgart (IMS CHIPS), Stuttgart D-70569, Germany
2. Faculty Mechanical and Medical Engineering (MME), Institute for Microsystems Technology (iMST), Rottweil D-78628, Germany
3. Laboratory for Biomedical Microtechnology, Department of Microsystems Engineering-IMTEK, University of Freiburg, Freiburg D-79110, Germany
4. BrainLinks-Braintools//IMBIT, University of Freiburg, Freiburg D-79110, Germany
5. Institute for Nano- and Microelectronic Systems (INES), University of Stuttgart, Stuttgart D-70569, Germany