A robust batch-fabricated high-density cochlear electrode array

This paper reports a fully batch-fabricated cochlear electrode array with built-in curl and stiffness control. The array is fabricated from stacked layers of parylene and metal with an integrated backing structure formed by parylene rings. The dual-function rings set the stiffness of the device and allow the array to be positioned inside the cochlea using a standard stylet wire approach. Metal-based stress-compensated layers are used to pre-curl the array so that it hugs the modiolus after insertion. A 32-site array with IrO sites on 250 ¿m centers is realized.