Title :
Perforated silicon nerve chips with doped registration electrodes: in vitro performance and in vivo operation
Author :
Wallman, Lars ; Levinsson, A. ; Schouenborg, Jens ; Holmberg, H. ; Danielsen, N. ; Laurell, T.
Author_Institution :
Dept. of Electr. Meas., Lund Inst. of Technol., Sweden
Abstract :
An in vitro model was developed for the study of signal transduction between a Cu-wire, mimicking a neural signal source, and recording electrodes on perforated silicon chips. Phosphorous doped electrodes were used to achieve an all-silicon device. The model was used to study signal amplitude as a function of the spatial position, and distance to the signal source. Recordings of the signal crosstalk to neighboring electrodes on the chips were made. It was found that the amplitude decreased by a factor of two at a distance of 50 μm between the electrode surface and the signal source. The chip electrode signal crosstalk was found to be 6 dB using an external reference electrode. Improvements were accomplished with an on chip reference electrode giving a crosstalk suppression of 20 dB. Impedance analysis showed that doped silicon electrodes displayed similar characteristics as Cu-electrodes at frequencies above 3 kHz. Sieve electrodes were implanted in the rat sciatic nerve and following a 10-week nerve regeneration period the dorsal and ventral (L5) roots in the spinal cord were stimulated. Compound action potentials were recorded via the chip. Stimulating the regenerated sciatic nerve via the sieve electrode also induced lower leg muscle contraction activity.
Keywords :
biocontrol; bioelectric potentials; biomedical electrodes; crosstalk; microelectrodes; neural chips; neuromuscular stimulation; prosthetics; Cu-wire; Si; all-silicon device; compound action potentials; crosstalk suppression; doped registration electrodes; impedance analysis; in vitro model; in vitro performance; in vivo operation; lower leg muscle contraction activity; neighboring electrodes; nerve regeneration; neural interface; neural prosthesis; neural signal source; on chip reference electrode; perforated silicon nerve chips; phosphorous doped electrodes; rat sciatic nerve; sieve electrodes; signal crosstalk; signal registration; signal transduction; spinal cord; Crosstalk; Electrodes; Frequency; In vitro; In vivo; Leg; Muscles; Silicon; Spinal cord; Surface impedance; Action Potentials; Animals; Biocompatible Materials; Copper; Decerebrate State; Electric Conductivity; Electric Stimulation; Electrodes, Implanted; Equipment Design; Female; Materials Testing; Models, Neurological; Neurons; Pilot Projects; Rats; Rats, Wistar; Sciatic Nerve; Signal Transduction; Silicon; Spinal Cord; Spinal Nerve Roots;
Journal_Title :
Biomedical Engineering, IEEE Transactions on