Scalable, Modular Three-Dimensional Silicon Microelectrode Assembly via Electroless Plating

Abstract

We devised a scalable, modular strategy for microfabricated 3-D neural probe synthesis. We constructed a 3-D probe out of individual 2-D components (arrays of shanks bearing close-packed electrodes) using mechanical self-locking and self-aligning techniques, followed by electroless nickel plating to establish electrical contact between the individual parts. We detail the fabrication and assembly process and demonstrate different 3-D probe designs bearing thousands of electrode sites. We find typical self-alignment accuracy between shanks of <0.2° and demonstrate orthogonal electrical connections of 40 µm pitch, with thousands of connections formed electrochemically in parallel. The fabrication methods introduced allow the design of scalable, modular electrodes for high-density 3-D neural recording. The combination of scalable 3-D design and close-packed recording sites may support a variety of large-scale neural recording strategies for the mammalian brain.

Electrochemical Redox Cycling Behavior of Gold Nanoring Electrodes Microfabricated on a Silicon Micropillar

“…Nanoelectrodes (NEs) with their unique size-dependent properties are widely utilized as detectors in several areas of (bio-) electrochemistry, which includes nanoelectrode lithography, single cell analysis, scanning electrochemical microscopy (SECM), and many others [1][2][3][4][5]. NEs are superior to microelectrodes in terms of their higher signal-to-noise ratio (SNR), higher sensitivity, lower detection limits, smaller volume probed, higher mass transport rates owing to radial-type diffusion, more rapid detection, higher spatial-temporal resolution, and the ability to apply them to highly resistive media [6][7][8][9].…”

Profiling neurons surrounding subcellular-scale carbon fiber electrode tracts enables modeling recorded signals

“…Currently, the most widely used intracortical electrodes are composed of silicon shanks fabricated using standard cleanroom techniques 6 . These electrodes are becoming increasingly sophisticated, with newer designs approaching or exceeding a thousand densely-packed recording sites [7][8][9][10][11] . For example, the Neuropixels probe has demonstrated simultaneous recording from hundreds of individual neurons along its length 8,9,12 .…”

“…Planar silicon electrode arrays, e.g., the Utah Electrode Array (UEA), can sample wide areas of cortex 13 for use in BMIs 14 , enabling the restoration of function lost to neurological disease [15][16][17] . Moreover, the recent advancements of multi-shank Michigan-style electrodes 10 , such as the Neuropixels 2.0 9 , and variable-length UEA-style electrodes, such as the Sea of Electrodes Array 7 , signify that recording neuronal populations in 3D is possible.…”

Micro-Compression Characterization and Thermal Stability of Electrolessly Plated Nickel Phosphorus Alloy

“…Nickel-based materials have excellent properties such as high corrosion resistance, 1 electrical conductivity 2,3 and mechanical strength, 4,5 which are beneficial for application in electronic devices. Nickel materials having complex structure toward electronic components could be prepared by direct current electrodeposition 6,7 when the substrate is electrically conductive, or electroless plating when the substrate is not electrically conductive.…”