Evaluation of the packaging and encapsulation reliability in fully integrated, fully wireless 100 channel Utah Slant Electrode Array (USEA): Implications for long term functionality

The encapsulation and packaging reliability in fully integrated, fully wireless 100 channel Utah Slant Electrode Array (USEA)/integrated neural interface-recording version 5 (INI-R5) has been evaluated by monitoring the extended long term in vitro functional stability and recording longevity. The INI encapsulated with 6-μm Parylene-C was immersed in phosphate buffer saline (PBS) at room temperature for a period of over 12 months. The USEA/INI-R5, while being soaked was powered and configured wirelessly through 2.765 MHz inductive link and the transmitted frequency shift keying (FSK) modulated radio-frequency (RF) (900 MHz industrial, scientific, medical-ISM band) signal was also recorded wirelessly as a function of soak time. In order to test the long term recording ability, in vitro wireless recording was performed in agarose for few channels. The full functionality and the ability of the electrodes to record artificial neural signals even after 12 months of PBS soak provides a measure of encapsulation reliability, the functional and recording stability in fully integrated wireless neural interface and potential usefulness for future chronic implants.