Protuberant Electrode Structures for Subretinal Electrical Stimulation: Modeling, Fabrication and in vivo Evaluation

Area of Science:

• Biomedical Engineering
• Neuroscience
• Materials Science

Background:

• Neural interfaces utilize extracellular electrical stimulation for therapeutic applications.
• Retinal implants aim to restore vision in patients with photoreceptor degeneration (e.g., AMD, RP).
• Key design considerations include stimulation efficiency, bio-interface optimization, and material biocompatibility.

Purpose of the Study:

• Investigate novel microelectrode geometries for subretinal stimulation.
• Develop and test 3D microelectrode structures for flexible retinal implants.
• Evaluate in vivo tissue adaptation and preliminary stimulation efficacy.

Main Methods:

• Finite element analysis for modeling 3D microelectrode structures.
• Development of a microfabrication process for flexible implants.
• In vivo testing for retinal tissue adaptation and preliminary stimulation.

Main Results:

• Successful modeling and fabrication of 3D microelectrode structures with wells and mushroom-shaped electrodes.
• Demonstrated in vivo compatibility and adaptation of retinal tissue to the flexible implants.
• Preliminary in vivo stimulation experiments initiated.

Conclusions:

• Novel 3D microelectrode geometries show potential for improved subretinal stimulation.
• The developed microfabrication process is suitable for creating flexible neural implants.
• Further research is warranted to optimize these interfaces for vision restoration.