# Enabling Technology for a Biomimetic Artificial Retinal Chemical Synapse Chip

> **NIH NIH R21** · UNIVERSITY OF ILLINOIS AT CHICAGO · 2020 · $314,599

## Abstract

Project Summary:
The long-term goal of this study is to develop a novel biomimetic retinal neural interface for treating vision loss
from incurable blinding diseases such as age-related macular degeneration and retinitis pigmentosa that affect
millions of Americans. Vision loss in these diseases is due to gradual death of light-sensitive photoreceptor cells
in the retina at the back of the eye. The photoreceptors normally convert the visual stimuli into electrochemical
signals that are relayed to the brain for the perception of sight through a complex neural network. Their
degeneration impairs the ability of the retina to detect light and initiate vision. Retinal prostheses seeking to
restore the lost function of photoreceptors by stimulating surviving cells with electrical current are emerging as a
promising option for treating such blindness. However, they have difficulty restoring naturalistic vision and visual
acuity below the legal blindness limit. The main barrier to achieving better visual acuity with current retinal
prostheses is the stimulus agent because electrical current is an unnatural stimulus for cells. To overcome this
barrier, we propose a fundamentally different approach: a retinal prosthesis that transforms visual stimuli into
chemical stimuli just like natural photoreceptors. Stimulating live retinal tissues in a dish with the brain chemical
glutamate has been shown to mimic its natural activation following visual stimulation. Therefore, artificially
stimulating the retina with glutamate delivered through a prosthetic device implanted in the back of the eye could
potentially circumvent the limitations of current retinal prostheses. Our goal in this R21 application is to innovate
and develop such a device called artificial retinal chemical synapse (ARCS) chip that stimulates surviving retinal
cells with glutamate directly in response to visual stimuli just like photoreceptors through an interdisciplinary
collaboration, combining the varied fields of microsystems, optofluidics, biology and visual neuroscience. The
ARCS chip is an implantable optofluidic device that would deliver therapeutic amounts of glutamate into the
retina wirelessly and spatiotemporally in response to natural light through an array of microscopic organic solar
cell-powered hollow microneedles. This technology will obviate the need for any auxiliary power, complex
electronics to capture and process images and to detect the direction of gaze as required in current retinal
prostheses. We will develop this enabling technology through the following two specific aims: 1) Design and
fabricate a prototype ARCS chip. We will develop an optofluidic device for light-controlled spatiotemporal delivery
of glutamate into the retina. 2) Evaluate the neural interface functionality of the prototype ARCS chip. We will
test the ability of the optofluidic device to biomimetically stimulate the retina by interfacing it with a piece of retinal
tissue explanted from a photorecept...

## Key facts

- **NIH application ID:** 9931214
- **Project number:** 5R21EB028069-02
- **Recipient organization:** UNIVERSITY OF ILLINOIS AT CHICAGO
- **Principal Investigator:** John D Finan
- **Activity code:** R21 (R01, R21, SBIR, etc.)
- **Funding institute:** NIH
- **Fiscal year:** 2020
- **Award amount:** $314,599
- **Award type:** 5
- **Project period:** 2019-06-01 → 2022-08-31

## Primary source

NIH RePORTER: https://reporter.nih.gov/project-details/9931214

## Citation

> US National Institutes of Health, RePORTER application 9931214, Enabling Technology for a Biomimetic Artificial Retinal Chemical Synapse Chip (5R21EB028069-02). Retrieved via AI Analytics 2026-05-28 from https://api.ai-analytics.org/grant/nih/9931214. Licensed CC0.

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