Development of microelectrode arrays for artificial retinal implants using liquid crystal polymers.

Area of Science:

• Biomaterials Science
• Neuroscience
• Medical Devices

Background:

• Developing long-term implantable retinal prostheses is crucial for vision restoration.
• Existing microelectrode arrays face challenges in biocompatibility and mechanical stability.

Purpose of the Study:

• To create a novel liquid crystal polymer (LCP)-based microelectrode array for long-term retinal implantation.
• To evaluate the safety, biocompatibility, and functionality of the LCP array.

Main Methods:

• Utilized laser micromachining and thermal-press bonding for LCP array fabrication.
• Conducted in vitro reliability tests (impedance, adhesion) and in vivo animal studies.
• Assessed long-term biocompatibility and functionality using Optical Coherence Tomography (OCT) and electrically evoked cortical potentials (EECPs) in rabbit models.

Main Results:

• Fabricated LCP arrays exhibited smooth edges and moderate flexibility for safe implantation.
• Arrays showed no degradation after accelerated aging tests and maintained interlayer adhesion for over two months.
• In vivo implantation in rabbit suprachoroidal space was successful, with EECPs recorded and no adverse chorioretinal effects observed over three months.

Conclusions:

• Liquid crystal polymer (LCP)-based flexible microelectrode arrays are suitable for retinal prostheses.
• The developed arrays are safe, biocompatible, and mechanically stable for chronic retinal implant applications.