Integration Of An Optoelectronic, Flexible Neural Stimulator For Implantable Retinal Prosthesis

Abstract: Degenerative retinal disorders such as Age-related Macular Degeneration (AMD) and Retinitis Pigmentosa (RP) cause millions of people worldwide to lose their natural photoreceptors and can lead to irreversible loss of vision. Nanovision Biosciences has innovated an implantable retinal prosthesis system that replace the damaged photoreceptors with an optoelectronic neural stimulating array placed underneath the retina. In this talk, we present the integration of the silicon optoelectronic device array and biocompatible flexible substrates to be surgically implanted in the patient’s affected eye. We also present the development and design of the flexible circuit, based on mechanical simulation study, physical analysis by implantations in cadaver eyes or live animals, and haptic feedback from the surgical team. The assembly process with Si dielets and flex, including the flex transfer technique with thermal tape, dielet bonding with pick and place tools, and Si dielet sidewall encapsulation, will be discussed. The retinal prosthesis implant must remain functional and safe for use for as long as possible in the corrosive environment inside the human eye. We designed and conducted accelerated lifetime testing of the implantable devices to estimate their expected lifespan and to identify possible failure mechanisms during long-term operation before moving forward to human trials. While testing is still ongoing, we present the experimental considerations for the accelerated aging evaluation of this unique device. Bio: Dr. Yu-Hsin Liu is a senior member of the Nanovision team and leads device nanofabrication engineering for their first prosthesis system. She’s also involved in Si-to-flex assembly process development, electrochemical testing for neural stimulators, and lifetime testing establishment. She has 10 years of experience in micro/nano fabrication, process design, and characterization for optoelectronic and biomedical devices. She has a PhD in Materials Science and Engineering from UCSD. Her extensive technical experience has delivered more than 10 peer-reviewed publications and 3 patents in photodetection and retinal prosthesis applications.