ABSTRACT
There is clearly a need for microelectrodes on the same size scale as cells in both
stimulation and recording applications. When stimulating neural tissue, the
higher localization of current afforded by small electrodes may lead to higher
stimulation efficiency [1, 2]. Smaller and more densely spaced microelectrodes
can record neural activity from smaller volumes of neurons. However, following
implantation a cellular encapsulating sheath consisting of glial cells envelops
the microelectrode array [3]. The glial cells involved in the tissue reaction are
on the same length scale as the microelectrodes themselves. The tissue reaction
will increase the electrode-tissue interface impedance and will therefore alter
the path of current flow, thus decreasing the specificity with which the device
can stimulate or record from small volumes of neurons [4].
