Custom-designed high-density conformal planar multielectrode arrays for brain slice electrophysiology

Gholmieh, Ghassan; Soussou, Walid; Han, Martin; Ahuja, Ashish; Hsiao, Min-Chi; Song, Dong; Tanguay, Armand R.; Berger, Theodore W.

doi:10.1016/j.jneumeth.2005.08.021

Cited by 44 publications

(40 citation statements)

References 44 publications

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“…Two groups, each containing 14 microelectrodes, were fabricated on each substrate; the radii of the microelectrodes were 11, 25, 50, 150, 175, 200, 225, 250, 275, 300, and 325 μm. The details of the two photomask microfabrication process flow are described elsewhere [18]. The trace length was kept constant (26±1.5 mm) for all electrodes and the associated resistance of the platinum traces was 81.0 ± 1.6 Ω.…”

Section: Methodsmentioning

confidence: 99%

The Dependence of Spectral Impedance on Disc Microelectrode Radius

Ahuja

Behrend

Whalen

et al. 2008

IEEE Trans. Biomed. Eng.

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As microelectrodes gain widespread use for electrochemical sensing, biopotential recording, and neural stimulation, it becomes important to understand the dependence of electrochemical impedance on microelectrode size. It has been shown mathematically that a disc electrode, coplanar in an insulating substrate and exposed to a conducting media, exhibits an inhomogeneous current distribution when a potential step is applied. This distribution is known as the primary distribution, and its derivation also yielded an analytic solution for electrical resistance of the conducting media (R s ), between the disc surface and a distant ground, which is inversely proportional to disk radius [R s = 1/(4kr), where k is media conductivity and r is disk radius]. The dependence of spectral impedance on microelectrode radius, however, has not been explored. We verify the analytical solution for resistance using high-frequency (100 kHz) electrochemical impedance data from microelectrodes of varying radius (11-325 μm). For all disc radii, as we approach a lower frequency (→10 Hz), we observe a transition from radial to area dependence (e.g., 1/r → 1/r 2 ). We hypothesize that this transition is driven by the fact that the derivation of the primary distribution ignores concentration gradients, but that these gradients cannot be ignored at lower frequencies.

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Section: Methodsmentioning

confidence: 99%

The Dependence of Spectral Impedance on Disc Microelectrode Radius

Ahuja

Behrend

Whalen

et al. 2008

IEEE Trans. Biomed. Eng.

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“…Details of the two photomask photolithographic process flow for fabrication of MEAs with Pt leads and silicon nitride/SU-8 insulation are described elsewhere [34], [35].…”

Section: B Custom Multielectrode Arraysmentioning

confidence: 99%

AnIn VitroModel of a Retinal Prosthesis

Ahuja

Behrend

Kuroda

et al. 2008

IEEE Trans. Biomed. Eng.

104

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Epiretinal prostheses are being developed to bypass a degenerated photoreceptor layer and excite surviving ganglion and inner retinal cells. We used custom microfabricated multielectrode arrays with 200-μm-diameter stimulating electrodes and 10-μm-diameter recording electrodes to stimulate and record neural responses in isolated tiger salamander retina. Pharmacological agents were used to isolate direct excitation of ganglion cells from excitation of other inner retinal cells. Strength-duration data suggest that, if amplitude will be used for the coding of brightness or gray level in retinal prostheses, shorter pulses (200 μs) will allow for a smaller region in the area of the electrode to be excited over a larger dynamic range compared with longer pulses (1 ms). Both electrophysiological results and electrostatic finite-element modeling show that electrodeelectrode interactions can lead to increased thresholds for sites half way between simultaneously stimulated electrodes (29.4 ± 6.6 nC) compared with monopolar stimulation (13.3 ± 1.7 nC, p < 0.02). Presynaptic stimulation of the same gan-glion cell with both 200-and 10-μm-diameter electrodes yielded threshold charge densities of 12 ± 6 and 7.66 1.30 nC/cm 2 , respectively, while the required charge was 12.5 ± 6.2 and 19 ± 3.3 nC.

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“…60 R 64 R ITO tracks with Ø 28 -36 µm or 36 x 36 µm 2 Au-or Pt-coated electrodes on glass in a tissue-"conformal" arrangement, insulated by Si 3 N 4 or SU-8 (Gholmieh et al, 2006) (Giovangrandi et al, 2006) S. Rajaraman M.G. Allen et al 12 -13 R (3D) Laser scribed, electroplated Ni/Cu/Pt-black electrodes (Ø < 10 µm) on a SU-8 microtower (fluidic) structure (< 500 µm height) on perforated fused silica insulated by parylene (Rajaraman et al, 2007) 25 R (spike, 3D) + 25 R (planar) 300 -500 µm high, Ø 50 µm Au/Cr spike-tip or Ø 50 µm Au planar electrodes through metal transfer micromolding (MTM) in PDMS on SU-8, PMMA, or PU carrier with parylene insulator either selectively laser-and globally RIE-(CHF 3 /O 2 plasma) deinsulated at the electrode sites, or applied during "capping protection" of the electrode sites.…”

Section: R+49smentioning

confidence: 99%

Prospects for Neuroprosthetics: Flexible Microelectrode Arrays with Polymer Conductors

Blau¹

2011

Applied Biomedical Engineering

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Custom-designed high-density conformal planar multielectrode arrays for brain slice electrophysiology

Cited by 44 publications

References 44 publications

The Dependence of Spectral Impedance on Disc Microelectrode Radius

The Dependence of Spectral Impedance on Disc Microelectrode Radius

AnIn VitroModel of a Retinal Prosthesis

Prospects for Neuroprosthetics: Flexible Microelectrode Arrays with Polymer Conductors

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