A Neural Probe With Up to 966 Electrodes and Up to 384 Configurable Channels in 0.13 $\mu$m SOI CMOS

In vivo recording of neural action-potential and local-field-potential signals requires the use of high-resolution penetrating probes. Several international initiatives to better understand the brain are driving technology efforts towards maximizing the number of recording sites while minimizing the neural probe dimensions. We designed and fabricated (0.13-μm SOI Al CMOS) a 384-channel configurable neural probe for large-scale in vivo recording of neural signals. Up to 966 selectable active electrodes were integrated along an implantable shank (70 μm wide, 10 mm long, 20 μm thick), achieving a crosstalk of -64.4 dB. The probe base (5 × 9 mm²) implements dual-band recording and a 171.6 Mbps digital interface. Measurement results show a total input-referred noise of 6.4 μV_rms and a total power consumption of 49.1 μW/channel.

I. Introduction

Large-scale in vivo recording of neuron populations has emerged as a key approach towards understanding how neural networks in the brain work [1]. Microfabricated silicon neural probes have established as the dominant technology in this field and have achieved ever increasing densities and numbers of simultaneous recording electrodes while reducing the probe-shank dimensions for minimal tissue damage [2]– [10]. A high electrode density is crucial in order to increase the spatial resolution and thus the accuracy of identifying individual neurons from large populations [11]. A large number of simultaneously-recorded electrodes, on the other hand, increases tissue coverage and allows recording from many neurons spanning multiple brain regions, thus providing insight into specific behaviors and self-organized processes encoded by neuron ensembles [12].