Sea of Electrodes Array (SEA): Customizable 3D High-Density High-Count Neural Probe Array Technology

Abstract:

Accurate mapping of neural circuits and interfacing with neurons for control of brain-machine interfaces require simultaneous large-scale and high spatiotemporal resolution recordings and stimulation of neurons in multiple layers and areas of the brain. Conventional penetrating multielectrode arrays (MEAs) are limited to a few thousand electrodes at best, with limited volumetric 3D spatial resolution. This is mainly due to the types of fabrication technologies and available designs and materials for making such probes. Based on the strengths and shortcomings of the available MEAs, we present a new fabrication technology for a new class of 3D neural electrode array that provides the characteristics of a near-ideal neural interface.

This research addresses some of the limitations of the previous works in terms of electrode scale, density and spatial coverage (depth and span) by design, development, and fabrication technology using standard semiconductor manufacturing processes. In order to realize a scalable 3D array of extremely dense, slender, and sharp needles with recording sites at each of their tips, a number of techniques are developed.

Using these technologies, we have fabricated millimeter-long (1.2mm), narrow (10 to 20Â µm diameter), sharp, high-density (400 electrodes/mm2) high-count (5000+) silicon electrode arrays. Electrodes robustness, insertion and recording functionality have been demonstrated by acute in vivo recordings in a rat brain, where local field potentials (LFP) have been recorded.