Flexible MEMS Microelectrode Based On LIGA-like Micro-fabrication Technology

Applications of micro-electro-mechanical systems (MEMS) and micro-fabrication have spread to a new field of Bio-MEMS in recent years. As human’s life and health is getting more and more concern in recent years, the biomedical field MEMS device(Bio-MEMS) applications have gradually become a research hotspot in micro/Nano-Engineering field, especially for the biological prosthesis (the implantable drug-delivery systems, neurological stimulator and bone growth stimulators). Among these prostheses, Bio-MEMS devices used in neural interfaces for recording or stimulating neural activities have opened up tremendous opportunities for neural professions to establish a man-machine interface to the central or peripheral nervous system. Therefore, as the key part of the neural system, the study of microelectrode array has become one of the research hotspot in current. A new issue, using implantable micro-electrodes device to stimulate human stomach nerve, which aims to help people keep dieting has been raised.A MEMS-based flexible microelectrode array (MEA) is studied in this thesis, which is fabricated by SU-8inclined exposure technology, LIGA-like technology, magnetron sputtering. Based on Bio-medic and clinical uses considerations, a microelectrodes structure was designed for mouse’s stomach nerve (0.08mm diameter). According to the electrode materials, equipment etc, to select and optimize the design and determines the fabrication process. The key processes during the fabricating MEA is researched, include inclined exposure, PDMS molding, and oxygen Plasma treatment. The strain-resistance in silver films for PDSM-based flexible electrodes is testing researched. Finally, this study provides the improvement and prospect of the microelectrodes nerve stimulator.The fabricated electrode array is1x2. The space of two channels is240μm, the width of channel is80μm, the depth is40μm. The electrodes have an approximately90°inverted triangle surface profile. Compared to the traditional microelectrode, the electrode withinverted triangle geometry increases the surface, allows electrode to be close to target neurons,which is helpful to neural stimulation.