Honeycomb-shaped electro-neural interface enables cellular-scale pixels in subretinal prosthesis

Thomas Flores, Tiffany Huang, Mohajeet Bhuckory, Elton Ho, Zhijie Chen, Roopa Dalal, Ludwig Galambos, Theodore Kamins, Keith Mathieson, Daniel Palanker

Research output: Contribution to journalArticle

8 Citations (Scopus)

Abstract

High-resolution visual prostheses require small, densely packed pixels, but limited penetration depth of the electric field formed by a planar electrode array constrains such miniaturization. We present a novel honeycomb configuration of an electrode array with vertically separated active and return electrodes designed to leverage migration of retinal cells into voids in the subretinal space. Insulating walls surrounding each pixel decouple the field penetration depth from the pixel width by aligning the electric field vertically, enabling a decrease of the pixel size down to cellular dimensions. We demonstrate that inner retinal cells migrate into the 25 μm deep honeycomb wells as narrow as 18 μm, resulting in more than half of these cells residing within the electrode cavities. Immune response to honeycombs is comparable to that with planar arrays. Modeled stimulation threshold current density with honeycombs does not increase substantially with reduced pixel size, unlike quadratic increase with planar arrays. This 3-D electrode configuration may enable functional restoration of central vision with acuity better than 20/100 for millions of patients suffering from age-related macular degeneration.
Original languageEnglish
Article number10657
Number of pages12
JournalScientific Reports
Volume9
Issue number1
DOIs
Publication statusPublished - 23 Jul 2019

Keywords

  • visual prostheses
  • macular degeneration
  • sight restoration

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