LCP-based Retinal Prosthesis: Monolithically Integrated Implantable Stimulator

Abstract

Purpose: : For the chronically implantable retinal stimulation system, Liquid Crystal Polymer (LCP)-based wireless stimulator was proposed with monolithic integration. This work is related to the progress of SNU retinal implant toward a thin and flexible implantable stimulator which is long-term reliable and simple to fabricate.

Methods: : LCP-based microelectrode arrays were fabricated by previously reported methods (Lee SW, et al., IOVS 2009), and thermally formed LCP package lid was prepared for monolithic encapsulation. Planar spiral coil for receiving power and data was designed and fabricated on LCP substrate. The geometric parameters of planar coil were optimized by using finite element simulations. Microelectrode arrays and telemetry coil were integrated with stimulator ASIC and surrounding circuitries. Then, the assembled system was encapsulated into LCP package using thermal-bonding process to protect electronics in aqueous condition. The performance of this stimulation system was investigated.

Results: : LCP-based monolithically integrated system for wireless retinal stimulation was successfully fabricated and tested. It was shown that stimulator worked well after the thermal bonding process, and the maximum operating distance of telemetric link was approximately 19mm.

Conclusions: : The new LCP-based wireless retinal stimulation system was fabricated and its functionality was tested. Using this monolithic integration method, further work is currently under progress for development of thin and flexible stimulator which can conform to the curvature of implantation place.

Keywords: retina