Impedance Automatic Testing And Analyzing System For The Multichannel Flexible Thin-Film Microelectrode Array

Vision is the main source for the human to get information from the outside world, and blindness affects the quality of our life not only physically but also mentally. Nowadays, visual prosthesis is one of the focuses of visual function restoration research. This artificial device gathers and encodes outside image information, and then applies the electrical signals to microelectrode array to induce phosphenes in visual cortex. As the key component of visual prosthesis interacting with visual nerve tissue, the electrochemical impedance is an important evaluation parameter of the microelectrode. So, it is crucial to evaluate the electrochemical performance of the microelectrode array in vitro. With the development of MEMS (Micro-Electro-Mechanical System) techniques and performance requirements of electrode, multichannel flexible thin-film microelectrode array (MEA) has become the important component of retinal prosthesis. The traditional technique for testing multichannel flexible thin-film MEA may cause damage to the electrode. Meanwhile, mass and complex manual operation owing to high-number electrodes would cause measurement errors with low efficiency. Apparently, this traditional testing method can not meet our demands yet.Therefore, a set of impedance automatic testing and analyzing system used three-electrode testing equipment is developed by analyzing the electrochemical theory at the electrode-electrolyte interface, and used to test and analyze the electrochemical impedance of retinal microelectrode array in this thesis. The system can automatically test the impedance by the virtual instrument control of testing instruments and multichannel switches, automatically draw the impedance and phase spectrum chart for each channel, and then calculate the mean and variance values of the whole electrodes impedance and phase, Besides, all the data can be saved as an Excel file. A simple, efficient, high-precision approach to impedance automatic testing, data automatic analysis and processing, and filing of the system provide an effective evaluation method for the MEA impedance.