Characterization of an Elastically Stretchable Microelectrode Array and Its Application to Neural Field Potential Recordings

Elastically stretchable microelectrode arrays (SMEAs) were fabricated, and their functionality was tested by recording field potentials from neural tissue. The SMEA includes 11 microelectrodes, each with a recording area of 100x200 mu m and a reference electrode. The microelectrodes were fabricated by depositing and patterning thin-film gold conductors on the elastomeric substrate poly(dimethylsiloxane). A photopatternable silicone was used to encapsulate the microelectrodes and pattern vias for electrical contact. The recording sites of the microelectrodes were electroplated with platinum black to reduce the impedance of the electrode/electrolyte interface. Spontaneous and stimulus-evoked activity was recorded from hippocampal slices placed on an array that was biaxially stretched up to 13.3%. No appreciable difference in microelectrode properties was detected before and after stretching, demonstrating that the microelectrodes can be stretched reversibly.