title: A silicon neural probe fabricated using DRIE on bonded thin silicon.
abstract: A silicon neural probe fabricated using a deep reactive ion etching based process on 250 μm thin silicon wafers was developed. The fabricated probes replicate the design of soft parylene-C based probes embedded in dissolvable needles and can therefore also be used to test the encapsulation properties of parylene-C in-vivo without introducing additional effects introduced by the dissolvable gel. The process also demonstrates the possibility of performing conventional photolithography on substrates bonded to a handle wafer using a backgrinding liquid wax (BGL7080) as an adhesive. This technique would allow integration of Si wafer thinning into the fabrication of neural probes, potentially allowing a range of neural probes of different thicknesses to be fabricated. Fabricated probes were characterized using electrochemical impedance spectroscopy (EIS) yielding a measured impedance value of ~80 kΩ at 1 kHz for 15 μm by 115 μm platinum electrodes, indicating that extracellular neural recordings are possible. The neural probes were inserted into the substantia nigra of a mouse that showed successful recording of neural activity. Probes fabricated using this technique can thus be potentially used in the study of Parkinson's disease.
authors.lastname: Xiao Chuan Ong
authors.forename: Amanda
authors.initials: A
authors.lastname: Willard
authors.forename: Mats
authors.initials: M
authors.lastname: Forssell
authors.forename: Aryn
authors.initials: A
authors.lastname: Gittis
authors.forename: Gary K
authors.initials: GK
authors.lastname: Fedder
mesh_terms: D000200:Action Potentials / Q000502:physiology; D000268:Adhesiveness; D000818:Animals; D058266:Dielectric Spectroscopy; D004566:Electrodes; D007477:Ions; D008810:Mice, Inbred C57BL; D058117:Neural Prostheses; D061848:Optical Imaging; D011108:Polymers / Q000737:chemistry; D012825:Silicon / Q000737:chemistry*; D014992:Xylenes / Q000737:chemistry
chemical_list: D007477:Ions; D011108:Polymers; D014992:Xylenes; C011055:parylene; D012825:Silicon