Mechanical characterization of neural electrodes based on PDMS-parylene C-PDMS sandwiched system

Manufacturing of neural electrodes based on metal foil and silicone rubber using a laser is a simple and promising method. A handicap of such electrode arrays is the mechanical robustness of the thin metal tracks that connect the electrode sites with the interconnection pads. Embedding of structured parylene C foil in silicone rubber turned out to be an interesting method to increase the robustness. Test samples with 12.5 μm thick platinum tracks and a 15 μm thick embedded and RIE-structured parylene C foil showed more than 800 % higher ultimate strength until breakage of the tracks. Different structured parylene C foil showed increasing robustness with increasing hole-spacing.