Hostname: page-component-8448b6f56d-gtxcr Total loading time: 0 Render date: 2024-04-24T08:26:31.012Z Has data issue: false hasContentIssue false

Mechanical and Electrical Reliability of a Chronically Implanted Metal-Polyimide Electrode Array

Published online by Cambridge University Press:  01 February 2011

John D. Yeager
Affiliation:
johnyeager@wsu.edu, Washington State University, Mechanical and Materials Engineering, Pullman, Washington, United States
Derrick J. Phillips
Affiliation:
djphillips0@gmail.com, Washington State University, Veterinary and Comparative Anatomy, Pharmacology & Physiology, Pullman, Washington, United States
David M. Rector
Affiliation:
drector@vetmed.wsu.edu, Washington State University, Veterinary and Comparative Anatomy, Pharmacology & Physiology, Pullman, Washington, United States
David F. Bahr
Affiliation:
dbahr@wsu.edu, United States
Get access

Abstract

A flexible electrode array consisting of a thin metal film on a polymer substrate has been developed for neural implantation in rats. The biocompatible arrays record cortical brain signals from awake and mobile rats in order to gather significant neurological data. Four point bend testing of the metal-Kapton system has been used to characterize the interfacial toughness, and therefore the mechanical durability, of the array. Several different adhesion layers on were evaluated using this method. Use of a titanium-tungsten interlayer increases the mixed-mode fracture toughness from approximately 1 J/m2 to approximately 2 J/m2, while a titanium interlayer provides a toughness of more than 4 J/m2. Gold-Kapton arrays were implanted in rats for periods exceeding 200 days, and neural recordings were taken frequently. The arrays exhibit excellent long-term reliability, with no decrease in signal recording capability over the course of the implantation.

Type
Research Article
Copyright
Copyright © Materials Research Society 2009

Access options

Get access to the full version of this content by using one of the access options below. (Log in options will check for institutional or personal access. Content may require purchase if you do not have access.)

References

REFERENCES

1. Jones, M.S. and Barth, D.S.. Spatiotemporal organization of fast (>200Hz) electrical oscillations in rat vibrissa/barrel cortex. Journal of Neurophysiology 82, 3 (1999) 1599–609200Hz)+electrical+oscillations+in+rat+vibrissa/barrel+cortex.+Journal+of+Neurophysiology+82,+3+(1999)+1599–609>Google Scholar
2. Strumwasser, F.. Long-Term Recording from Single Neurons in Brain of Unrestrained Mammals. Science 127 (1958) 469–70Google Scholar
3. Polikov, V.S., Tresco, P.A., and Reichert, W.M.. Response of brain tissue to chronically implanted neural electrode. Journal of Neuroscience Methods 148 (2005) 118 Google Scholar
4. Hollenberg, B.A., Richards, C.D., Richards, R., Bahr, D.F., and Rector, D.M.. A MEMS fabricated flexible electrode array for recording surface field potentials. Journal of Neuroscience Methods 153, 1 (2006) 147–53Google Scholar
5. Yeager, J.D, Phillips, D.J., Rector, D.M., and Bahr, D.F.. Characterization of flexible ECoG electrode arrays for chronic recording in awake rats. Journal of Neuroscience Methods 173, 2 (2008) 279–85Google Scholar
6. Stieglitz, T., Beutel, H., Schuettler, M., and Meyer, J.. Micromachined, polyimide-based devices for flexible neural interfaces. Biomedical Microdevices 2, 4 (2000) 283–94Google Scholar
7. Huang, Z., Suo, Z., Xu, G., He, J., Prévost, J.H., and Sukumar, N.. Initiation and arrest of an interfacial crack in a four-point bend test. Engineering Fracture Mechanics 72 (2005) 2584–601Google Scholar
8. Litteken, C.S., Strohband, S., and Dauskardt, R.H.. Residual stress effects on plastic deformation and interfacial fracture in thin-film structures. Acta Materialia 53 (2005) 1955–61Google Scholar
9. Suo, Z., Hutchinson, J.W.. On sandwiched test specimens for measuring interface crack toughness. Materials Science & Engineering A 107 (1989) 135–43.Google Scholar