Abstract: In order to improve the long-term effectiveness of neural electrode, kinetic analysis of the micromotion at the electrode-brain interface was conducted using finite element simulation method. Compared with the traditional commercial electrode, the fish-bone-shaped electrode shows great effectiveness in reducing the micromotion induced injury. Moreover, the influence of the number of electrode shanks on micromotion induced injury of brain tissue was revealed. Based on the rationality and optimization principles of electrode site distribution, a novel multi-shank fish-bone-shaped electrode was developed. The electrode decreases the maximum strain, von Mises stress and total deformation of brain tissue by 73.23%, 48.78% and 76.92% respectively compared with the original one. In addition, the novel electrode performs better than the commercial three-shank electrode with the same size and site distribution when both of the electrodes collect the same electrical signal. The results reveal that the novel electrode reduces the strain in the brain tissue considerably, and is expected to improve the lifetime of electrode effectively.

Key words: neural electrode, micromotion, finite element method, multi-shank structure