Multi-channel micro neural probe fabricated with SOI

Silicon-on-insulator (SOI) substrate is widely used in micro-electro-mechanical systems (MEMS). With the buried oxide layer of SOI acting as an etching stop, silicon based micro neural probe can be fabricated with improved uniformity and manufacturability. A seven-record-site neural probe was formed by inductive-coupled plasma (ICP) dry etching of an SOI substrate. The thickness of the probe is 15 mu m. The shaft of the probe has dimensions of 3 mmx100 mu mx15 mu m with typical area of the record site of 78.5 mu m(2). The impedance of the record site was measured in-vitro. The typical impedance characteristics of the record sites are around 2 M Omega at 1 kHz. The performance of the neural probe in-vivo was tested on anesthetic rat. The recorded neural spike was typically around 140 mu V. Spike from individual site could exceed 700 mu V. The average signal noise ratio was 7 or more.

National Basic Research Program of China ("973" Project) 2005CB724302 National High-Tech Research and Development Program of China ("863" Project) 2007AA04Z329 2007AA03Z427 National Natural Science Foundation of China 60776024 Supported by the National Basic Research Program of China ("973" Project) (Grant No. 2005CB724302), the National High-Tech Research and Development Program of China ("863" Project) (Grant Nos. 2007AA04Z329, 2007AA03Z427) and the National Natural Science Foundation of China (Grant No. 60776024)