Devices

A 4 µm thick organic electrode array with 10 × 10 µm sites on 30 µm pitch that records single-neuron action potentials from the brain surface. NYU and collaborators, 2015.

Device — Cortical surface

NeuroGrid (PEDOT:PSS surface array)

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ECoG · PEDOT:PSS · organic electronics · conformable · spikes from surface · NYU · Buzsaki · academic · research

NeuroGrid (PEDOT:PSS surface array)

One-line verdict: A surface array dense and thin enough to isolate putative single neurons without penetrating the brain, shown in rats and intraoperatively in epilepsy patients.

Quick tags: Recording · Cortical surface · Species: Rat, human (intraoperative) · Published: 2015

Overview

What it is: An ultra-conformable electrode array built on an organic material (PEDOT:PSS) as the interface. Neuron-sized sites sit close together, so a spike seen on several neighboring sites can be used to isolate a putative single neuron from the surface.

Why it matters: It challenges the usual split between surface arrays (field potentials, no spikes) and penetrating arrays (spikes, tissue damage).

Status: Research tool. The paper reports rat recordings, with spiking activity showing consistent phase modulation for more than a week, and intraoperative recordings in patients undergoing epilepsy surgery.

Spec Card Grid

Identity

  • Authors: Dion Khodagholy, Jennifer N. Gelinas, Thomas Thesen, Werner Doyle, Orrin Devinsky, George G. Malliaras, György Buzsáki
  • Published: Nature Neuroscience 18:310-315, 2015
  • Species: rat; human (intraoperative)

Geometry & Architecture

  • Site size: 10 × 10 µm
  • Inter-electrode spacing: 30 µm
  • Film thickness: 4 µm
  • Interface material: PEDOT:PSS
  • Channel count: a 256-channel and a 64-channel version appear in the paper’s supplementary figures

Evidence and limits

  • Rat: putative single-neuron isolation from the surface; phase-modulated spiking stable over more than one week
  • Human: LFP-modulated spiking recorded intraoperatively
  • Not shown: chronic human implantation

Engineering Verdict

Strengths: conforms to curved cortex, no penetration, neuron-scale site density.

Limitations: single-unit isolation relies on spikes being visible on neighboring sites, so it depends on the array lying flat against the surface; chronic human data not reported in this paper.

References