Development and Fabrication of Modular Micro Sensors on Flexible Polymer Foils

A concept for the fabrication of modular micro sensors on flexible substrate materials is presented in this paper. This paper describes the development and fabrication of modular eddy current micro sensors on a 7 μm thick polymer layer. The modular eddy current micro sensors are fabricated on a standard Si wafer due to handling purposes during the sensor fabrication process. Initial investigations concentrated on the proof of principle of applying a deep reactive-ion etching (DRIE) process to remove the Si wafer in parts. The DRIE process was used to structure Si frames, which serve as a carrier for the modular eddy current micro sensors. To evaluate the fabricated eddy current micro sensors on a flexible polymer foil, electrical resistance measurements were accomplished. Furthermore, the micro sensors were tested in a temperature shock test chamber to proof the long-term stability of the micro systems.