CMOS-Based High-Density Silicon Microprobe Arrays for Electronic Depth Control in Intracortical Neural Recording

In vivo validation of the electronic depth control probes

“…The 180-μ m-wide, 80-μ m-thick, 4-mm-long, 19 ° tip angle penetrating shaft of the EDC device was realized using deep reactive ion etching (DRIE) of silicon [17]. The shaft is populated with 188 recording sites in two columns with an equal horizontal and vertical center pitch of 40 μ m. The 20-μ m-diameter recording sites were plated with Pt, measuring about 1 MOhm impedance at 1 kHz.…”

“…The shaft is populated with 188 recording sites in two columns with an equal horizontal and vertical center pitch of 40 μ m. The 20-μ m-diameter recording sites were plated with Pt, measuring about 1 MOhm impedance at 1 kHz. Each recording site can be connected internally to one of the eight output lines of the probe, and these output lines can be connected in turn to an outside amplifier [18,19]. The connection matrix, switching electronics, control, and input and output lines were integrated on the shaft of the probe, implemented by the 0.6-μ m CMOS process XC06 (X-FAB Semiconductor Foundries AG, Erfurt, Germany).…”

“…The GUI was written using the free multiplatform wxWidgets framework and DialogBlocks, based on C + + . Further details about the EDC probe fabrication and GUI and FPGA interfacing can be found elsewhere [17][18][19].…”

“…To overcome the fragility and tissue damage problem and establish large numbers of neuronal recording sites in a relatively wide brain area, we have developed electronic depth control (EDC) devices using MEMS or complementary metal-oxide semiconductor (CMOS) technology [12,15,17,20]. These devices resemble a regular silicon probe in shape; however, instead of having only a limited number of recording sites, they have 188 recording contacts occupying a considerably larger proportion of the area of their 4-mm long shaft.…”

“…Of the 188 possible contacts, eight sites can be electronically selected and routed out to an external amplifier to record neuronal activity simultaneously from the eight sites. The selected sites can be rapidly reconfigured, allowing the experimenter to record from widespread brain areas without physically moving the device [18,19].…”