Chronic Neural Recording Using Silicon-Substrate Microelectrode Arrays Implanted in Cerebral Cortex

TLDR

Cortical prostheses require improved implantable microelectrode arrays for chronic neural recording. The study aimed to evaluate the reliability and signal quality of silicon‑substrate micromachined probes for chronic recording. The authors implanted 14 silicon probes in ten rodents, with 93 % remaining functional throughout the assessment period. The probes consistently delivered high‑quality spike recordings for up to 127 days, with over 90 % of sites maintaining sufficient SNR, and histology showed a stable interface, confirming their suitability for long‑term cortical recording and as a foundation for human microscale neural interfaces.

Abstract

An important aspect of the development of cortical prostheses is the enhancement of suitable implantable microelectrode arrays for chronic neural recording. The objective of this study was to investigate the recording performance of silicon-substrate micromachined probes in terms of reliability and signal quality. These probes were found to consistently and reliably provide high-quality spike recordings over extended periods of time lasting up to 127 days. In a consecutive series of ten rodents involving 14 implanted probes, 13/14 (93%) of the devices remained functional throughout the assessment period. More than 90% of the probe sites consistently recorded spike activity with signal-to-noise ratios sufficient for amplitudes and waveform-based discrimination. Histological analysis of the tissue surrounding the probes generally indicated the development of a stable interface sufficient for sustained electrical contact. The results of this study demonstrate that these planar silicon probes are suitable for long-term recording in the cerebral cortex and provide an effective platform technology foundation for microscale intracortical neural interfaces for use in humans.