Novel method of fabricating self-dissolvable and freely floating neural array

Neural microelectrodes can record from and stimulate neurons in the central and peripheral nervous systems. They play a critical role for the development of neural prostheses to restore lost motor or sensory functions of the body. Existing commercial devices (such as the Utah array) exhibit a lifetime of few months to several years. For clinical applications, it is desirable for these microelectrodes to last multiple decades. One of the primary reasons for the short lifetime of these devices is the micromotion of the brain with respect to the electrode array, causing severe foreign body response. To address this friction between the brain and electrode array, we present a self-dissolvable microelectrode array, whose electrodes can freely float in the brain independent to each other. During insertion, the base of the array is still held together by the biocompatible and dissolvable material polyethylene glycol (PEG). Once implanted, the PEG dissolves in the biological fluid resulting in all electrodes freely floating in the neural tissue.