gms | German Medical Science

Objective: The objective of this project is to develop a flexible, multifunctional platform combining opto-electro and iono-electro components, utilizing organic electronic ionic pumps (OEIPs) powered by a photoactive device for retinal stimulation and recording.

Material and method: The fabrication of flexible microelectrode arrays (Flex-MEA 128) was carried out on a polyimide substrate with gold electrodes [1]. The electrical characterization of the electrodes was performed using electrical impedance spectroscopy (EIS) in potentiostat mode (Ivium Technology) with a three-electrode setup. To determine the power required for OEIP operation, a single ion exchange membrane was fabricated via spin coating of PEDOT:PSS followed by reactive ion etching. The ion exchange membrane was set between two reservoirs, source and target. Sodium (Na+), Potassium (K+), and Lithium (Li+) ions were tested, and the ionic transport through the membrane was characterized using amperometric measurements.

Further methods include the functional integration of photoactive devices with ionic pumps, followed by optimization of the fabrication processes and photoactive material properties for retinal stimulation.

Result: The Flex-MEA 128 was successfully fabricated, with electrode impedance values measured around 1 MΩ, consistent with previous data. For the ion exchange membrane, a direct relationship was observed between current flow and the diffusion coefficient of the ions tested.

Discussion: The development of this wireless, multifunctional photoactive and iono-electro active platform represents a novel approach for emulating retinal function and studying retinal degeneration.