PDMS-based conformable microelectrode arrays with selectable novel 3-D microelectrode geometries for surface stimulation and recording

A method for fabricating polydimethylsiloxane (PDMS) based conformable microelectrode arrays (MEAs) with selectable novel 3-D microelectrode geometries is presented. Simply recessed, conically recessed, exponentially recessed, and protruded-well microelectrodes have been fabricated on the MEA with a diameter as small as 10 mum. 3-D microelectrode geometry parameters (recess depth, recess slope & profile, and protrusion/planar) can be controlled independently during fabrication. Exponentially and conically recessed microelectrodes are promising in chronic stimulation applications, such as neural prostheses, for their production of a uniform current density profile during stimulation, which can minimize stimulation-induced tissue burning and electrode corrosion. Protruded-well microelectrodes potentially provide a closer and sealed contact to the target tissue surface, avoiding current leakage during stimulation and thus achieving better stimulation efficiency in both charge delivery and spatial specificity.