A micromachined silicon depth probe for multichannel neural recording

Abstract

A process of making a new type of silicon depth-probe microelectrode array is described using a combination of plasma and wet etch. The plasma etch, which is done using a low temperature oxide (LTO) mask, enables probe thickness to be controlled over a range from 5 to 90 mu. Bending tests show that the probe's mechanical strength depends largely on shank thickness. More force can be applied to thicker shanks while thinner shanks are more flexible. One can then choose a thickness and corresponding mechanical strength using the process developed. The entire probe shaping process is performed only at low temperature, and thus is consistent with the standard CMOS fabrication. Using the probe in recording from rat's somatosensory cortex, we obtained four channel simultaneous recordings which showed clear independence among channels with a signal-to-noise ratio performance comparable with that obtained using other devices.

Design and fabrication of a polyimide-based microelectrode array: Application in neural recording and repeatable electrolytic lesion in rat brain

“…Recent studies have applied silicon-based microelectrode arrays in chronic neural signal recordings (Bai et al, 2000;Csicsvari et al, 2003;Tae Hwan et al, 2000). However, micromotion at the tissue-electrode contact areas induced persistent inflammatory responses (Cheung, 2007), directly resulting in neuronal loss.…”

In Vivo Validation of Custom-Designed Silicon-Based Microelectrode Arrays for Long-Term Neural Recording and Stimulation

“…In the future, devices for the treatment of neurodegenerative diseases, including Parkinson's disease, epilepsy, and depression, may employ microelectrodes. Batch-processed microelectrodes have been developed using a variety of substrates, including silicon [1], [2], silicon-on-insulator [3], ceramic [4], and metal [5]. Despite these advances, there has been limited progress in demonstrating chronically-implantable systems that can continue to function for many months.…”

Hydrophilic modification of neural microelectrode arrays based on multi-walled carbon nanotubes

“…After alternating, the square waveform of a shock voltage was about ±1 V with period 0.2 ms, and the responsive amplitude (peak to peak) of the AP recorded with the treated MWCNT electrode which was about 275 μV with period 1 ms; the recorded data were marked with an SNR up to 40.12 dB. This SNR is defined as the quotient of the peak-to-peak value of the spike and the root mean square of the noise [51]. For data recorded with MEA based on MWCNT as grown, a smaller SNR, 24.69 dB, was obtained under the same conditions, or 0.61 of the ratio for the treated MWCNT electrode.…”