Micromotion-induced dynamic effects from a neuron probe and brain tissue interface

Brain cells interfaced with electrical neural implants are utilized to gain a better understanding of the functionality of our nervous system. One main problem that exists with these neural implants is the potential to cause injury to surrounding neural cells due to a discrepancy in stiffness values between the implant and surrounding brain tissue when subjected to mechanical micromotion of the brain. To evaluate the effects of the mechanical mismatch, a series of dynamic simulations are conducted to better understand the design enhancements required to improve the feasibility of the neuron probe. In addition, the brain tissue deformation near the interface of the neuron probe can give insight on the extent of injury to the brain due to relative micromotion. The simulations use a nonlinear transient explicit finite element code, LS-DYNA. A three-dimensional quarter-symmetry finite element model is utilized for the transient analysis to capture the time-dependent dynamic deformations on the brain tissue from the implant as a function of different frequency shapes and stiffness values.