Biomechanical analysis of silicon microelectrode-induced strain in the brain.

Published

Journal Article

The ability to successfully interface the brain to external electrical systems is important both for fundamental understanding of our nervous system and for the development of neuroprosthetics. Silicon microelectrode arrays offer great promise in realizing this potential. However, when they are implanted into the brain, recording sensitivity is lost due to inflammation and astroglial scarring around the electrode. The inflammation and astroglial scar are thought to result from acute injury during electrode insertion as well as chronic injury caused by micromotion around the implanted electrode. To evaluate the validity of this assumption, the finite element method (FEM) was employed to analyze the strain fields around a single Michigan Si microelectrode due to simulated micromotion. Micromotion was mimicked by applying a force to the electrode, fixing the boundaries of the brain region and applying appropriate symmetry conditions to nodes lying on symmetry planes. Characteristics of the deformation fields around the electrode including maximum electrode displacement, strain fields and relative displacement between the electrode and the adjacent tissue were examined for varying degrees of physical coupling between the brain and the electrode. Our analysis demonstrates that when physical coupling between the electrode and the brain increases, the micromotion-induced strain of tissue around the electrode decreases as does the relative slip between the electrode and the brain. These results support the use of neuro-integrative coatings on electrode arrays as a means to reduce the micromotion-induced injury response.

Full Text

Duke Authors

Cited Authors

  • Lee, H; Bellamkonda, RV; Sun, W; Levenston, ME

Published Date

  • December 2005

Published In

Volume / Issue

  • 2 / 4

Start / End Page

  • 81 - 89

PubMed ID

  • 16317231

Pubmed Central ID

  • 16317231

Electronic International Standard Serial Number (EISSN)

  • 1741-2552

International Standard Serial Number (ISSN)

  • 1741-2560

Digital Object Identifier (DOI)

  • 10.1088/1741-2560/2/4/003

Language

  • eng