Design And Test Of Microelectrode Array For Visual Prostheses Based On Finite Element Method

Implanted microelectrode array is the direct interface of the external electronic circuit system and the nervous system. With the rapid development of MEMS technology and neuroscience, it plays an important role in the field of neural rehabilitation. Microelectrode array can be classified into stimulating electrode and recording electrode in terms of functionality, penetrating electrode, flat electrode and cuff electrode in terms of shapes in order to meet the needs of different physical locations.The performance of implanted microelectrode array directly impact the effectiveness and reliability of a variety of neural rehabilitation system. The implanted microelectrode array has micron rating size, the same with neuron; at the same time, it needs to have good biological compatibility as a result of direct contact with biological tissue; the material of the electrode needs to meet a very high corrosion resistance requirement for long-term implantation. The study of microelectrode array has important scientific significance and broad research value.The artificial visual prosthesis for visual rehabilitation has been extensively researched and rapidly developed in the last ten years which brings new hope to the blind patients. In this paper, for the visual rehabilitation of the microelectrode array study, the design of the microelectrode array is optimized theoretically based on the finite element method using ANSYS finite element analysis software. And the performance of the microelectrode array is tested through in vitro and in vivo measurement.The main research contents include: firstly, to study basic electrochemical theory of the electrode - electrolyte interface and discuss the equivalent circuit model; Secondly, in view of platinum/iridium alloy wire penetrating microelectrode array, using the finite element analysis method to set up the model and analysis of electric field distribution around the electrodes to provide a theoretical guidance for the optimization of microelectrode array designed; thirdly, the production of platinum/iridium alloy wire microelectrode arrays, and their in vitro testing of the electrical properties (impedance testing, cyclic voltammetry testing and micro-current stimulation test) and in vivo electrophysiological experiments to assess; fourthly, to summarize key issues and challenges of the design and production for microelectrode array of visual prosthesis.