Numerical simulation of neural probe geometry parameters under brain micromotion

Abstract

Brain micromotion is one of the key factors that influence the longevity of neural probes. In order to improve the long-term stability of brain implanted electrodes, finite element (FE) models, utilizing hyper-viscoelastic constitutive equations, are developed to conduct a series of dynamic analysis of the neural probe-brain model. The influences of neural probe geometry parameters (e.g. tip fillet, wedge angle, wall thickness) on micromotion induced brain injury are investigated. The results show that fillet radius of 20 micrometers keeps both the maximum strain and injury zone in a small region while wedge angle of 70 degree leads to a 10.34% reduction in strain and 34.52% reduction in injury zone. Wall thickness of 15 micrometers generates the minimal injury zone and should be minimized under the condition of probe strength. The results will provide guidance on the development of novel neural probes with long-term stability.