A new parylene-based microfabrication process is presented for neural recording and drug delivery applications. We introduce a large design space for electrode placement and structural flexibility with a six mask process. By using chemical mechanical polishing, electrode sites may be created top-side, back-side, or on the edge of the device having three exposed sides. Added surface area was achieved on the exposed edge through electroplating. Poly(3,4-ethylenedioxythiophene) (PEDOT) modified edge electrodes having an 85-μm2 footprint resulted in an impedance of 200 kΩ at 1 kHz. Edge electrodes were able to successfully record single unit activity in acute animal studies. A finite element model of planar and edge electrodes relative to neuron position reveals that edge electrodes should be beneficial for increasing the volume of tissue being sampled in recording applications. © 2011 Springer Science+Business Media, LLC.
Seymour, J. P., Langhals, N. B., Anderson, D. J., & Kipke, D. R. (2011). Novel multi-sided, microelectrode arrays for implantable neural applications. Biomedical Microdevices, 13(3), 441–451. https://doi.org/10.1007/s10544-011-9512-z