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The enhanced electrochemical activity of nanostructured materials is readily exploited in energy devices, but their utility in scalable and human-compatible implantable neural interfaces can significantly advance the performance of clinical and research electrodes. We utilize low-temperature selective dealloying to develop scalable and biocompatible one-dimensional platinum nanorod (PtNR) arrays that exhibit superb electrochemical properties at various length scales, stability, and biocompatibility for high performance neurotechnologies. PtNR arrays record brain activity with cellular resolution from the cortical surfaces in birds and nonhuman primates. Significantly, strong modulation of surface recorded single unit activity by auditory stimuli is demonstrated in European Starling birds as well as the modulation of local field potentials in the visual cortex by light stimuli in a nonhuman primate and responses to electrical stimulation in mice. PtNRs record behaviorally and physiologically relevant neuronal dynamics from the surface of the brain with high spatiotemporal resolution, which paves the way for less invasive brain-machine interfaces.

Poly(3,4-ethylenenedioxythiophene) or PEDOT is a promising candidate for next-generation neuronal electrode materials but its weak adhesion to underlying metallic conductors impedes its potential. An effective method of mechanically anchoring the PEDOT within an Au nanorod (Au-nr) structure is reported and it is demonstrated that it provides enhanced adhesion and overall PEDOT layer stability. Cyclic voltammetry (CV) stress is used to investigate adhesion and stability of spin-cast and electrodeposited PEDOT. The Au-nr adhesion layer permits 10 000 CV cycles of coated PEDOT film in phosphate buffered saline solution without delamination nor significant change of the electrochemical impedance, whereas PEDOT coating film on planar Au electrodes delaminates at or below 1000 cycles. Under CV stress, spin-cast PEDOT on planar Au delaminates, whereas electroplated PEDOT on planar Au encounters surface leaching/decomposition. After 5 weeks of accelerated aging tests at 60 °C, the electrodeposited PEDOT/Au-nr microelectrodes demonstrate a 92% channel survival compared to only 25% survival for spin-cast PEDOT on planar films. Furthermore, after a 10 week chronic implantation onto mouse barrel cortex, PEDOT/Au-nr microelectrodes do not exhibit delamination nor morphological changes, whereas the conventional PEDOT microelectrodes either partially or fully delaminate. Immunohistochemical evaluation demonstrates no or minimal response to the PEDOT implant., (© 2018 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.)

We report a new hybrid integration scheme that offers for the first time a nanowire-on-lead approach, which enables independent electrical addressability, is scalable, and has superior spatial resolution in vertical nanowire arrays. The fabrication of these nanowire arrays is demonstrated to be scalable down to submicrometer site-to-site spacing and can be combined with standard integrated circuit fabrication technologies. We utilize these arrays to perform electrophysiological recordings from mouse and rat primary neurons and human induced pluripotent stem cell (hiPSC)-derived neurons, which revealed high signal-to-noise ratios and sensitivity to subthreshold postsynaptic potentials (PSPs). We measured electrical activity from rodent neurons from 8 days in vitro (DIV) to 14 DIV and from hiPSC-derived neurons at 6 weeks in vitro post culture with signal amplitudes up to 99 mV. Overall, our platform paves the way for longitudinal electrophysiological experiments on synaptic activity in human iPSC based disease models of neuronal networks, critical for understanding the mechanisms of neurological diseases and for developing drugs to treat them.

Scalable Thousand Channel Penetrating Microneedle Arrays on Flex for Multimodal and Large Area Coverage BrainMachine Interfaces (Adv. Funct. Keywords: arrays; brain; flexible; microneedles; microwires; thousand channels; transparent EN arrays brain flexible microneedles microwires thousand channels transparent 1 1 1 06/21/22 20220617 NES 220617 B Microneedle Arrays b In article number 2112045, Shadi A. Dayeh and co-workers have invented an advanced brain-computer interface with a flexible and moldable backing and penetrating microneedles, which are 10 times thinner than the human hair. Arrays, brain, flexible, microneedles, microwires, thousand channels, transparent. [Extracted from the article]

We report a new hybrid integration scheme that offers for the first time a nanowire-on-lead approach, which enables independent electrical addressability, is scalable, and has superior spatial resolution in vertical nanowire arrays. The fabrication of these nanowire arrays is demonstrated to be scalable down to submicrometer site-to-site spacing and can be combined with standard integrated circuit fabrication technologies. We utilize these arrays to perform electrophysiological recordings from mouse and rat primary neurons and human induced pluripotent stem cell (hiPSC)-derived neurons, which revealed high signal-to-noise ratios and sensitivity to subthreshold postsynaptic potentials (PSPs). We measured electrical activity from rodent neurons from 8 days in vitro (DIV) to 14 DIV and from hiPSC-derived neurons at 6 weeks in vitro post culture with signal amplitudes up to 99 mV. Overall, our platform paves the way for longitudinal electrophysiological experiments on synaptic activity in human iPSC based disease models of neuronal networks, critical for understanding the mechanisms of neurological diseases and for developing drugs to treat them. [ABSTRACT FROM AUTHOR]