Design and demonstration of an intracortical probe technology with tunable modulus.
Intracortical probe technology, consisting of arrays of microelectrodes, offers a means of recording the bioelectrical activity from neural tissue. A major limitation of existing intracortical probe technology pertains to limited lifetime of 6 months to a year of recording after implantation. A major contributor to device failure is widely believed to be the interfacial mechanical mismatch of conventional stiff intracortical devices and the surrounding brain tissue. We describe the design, development, and demonstration of a novel functional intracortical probe technology that has a tunable Young's modulus from ∼2 GPa to ∼50 MPa. This technology leverages advances in dynamically softening materials, specifically thiol-ene/acrylate thermoset polymers, which exhibit minimal swelling of < 3% weight upon softening in vitro. We demonstrate that a shape memory polymer-based multichannel intracortical probe can be fabricated, that the mechanical properties are stable for at least 2 months and that the device is capable of single unit recordings for durations up to 77 days in vivo. This novel technology, which is amenable to processes suitable for manufacturing via standard semiconductor fabrication techniques, offers the capability of softening in vivo to reduce the tissue-device modulus mismatch to ultimately improve long term viability of neural recordings. © 2016 Wiley Periodicals, Inc. J Biomed Mater Res Part A: 105A: 159-168, 2017.
Department of Materials Science and Engineering, The University of Texas at Dallas, Richardson, Texas, 75030.
Dustin M
DM
Simon
Department of Electrical and Computer Engineering, George Mason University, Fairfax, Virginia, 22030.
Hamid
H
Charkhkar
Department of Bioengineering, The University of Texas at Dallas, Richardson, Texas, 75030.
Conan
C
St John
Department of Bioengineering, The University of Texas at Dallas, Richardson, Texas, 75030.
Sakthi
S
Rajendran
Department of Bioengineering, The University of Texas at Dallas, Richardson, Texas, 75030.
Tong
T
Kang
Department of Bioengineering, The University of Texas at Dallas, Richardson, Texas, 75030.
Radu
R
Reit
Department of Bioengineering, The University of Texas at Dallas, Richardson, Texas, 75030.
David
D
Arreaga-Salas
Department of Molecular Neuroscience, The Krasnow Institute for Advanced Study, George Mason University, Fairfax, Virginia, 22030.
Daniel G
DG
McHail
Department of Molecular Neuroscience, The Krasnow Institute for Advanced Study, George Mason University, Fairfax, Virginia, 22030.
Gretchen L
GL
Knaack
Department of Bioengineering, The University of Texas at Dallas, Richardson, Texas, 75030.
Andrew
A
Sloan
Department of Bioengineering, The University of Texas at Dallas, Richardson, Texas, 75030.
Dane
D
Grasse
Department of Molecular Neuroscience, The Krasnow Institute for Advanced Study, George Mason University, Fairfax, Virginia, 22030.
Theodore C
TC
Dumas
Department of Bioengineering, The University of Texas at Dallas, Richardson, Texas, 75030.
Robert L
RL
Rennaker
Department of Bioengineering, The University of Texas at Dallas, Richardson, Texas, 75030.|Department of Bioengineering, George Mason University, Fairfax, Virginia, 22030.
Joseph J
0000-0001-8276-3690
JJ
Pancrazio
Department of Materials Science and Engineering, The University of Texas at Dallas, Richardson, Texas, 75030.|Department of Bioengineering, The University of Texas at Dallas, Richardson, Texas, 75030.
Walter E
0000-0003-0135-0531
WE
Voit
D000818:Animals; D058256:Brain Waves; D055119:Elastic Modulus; D004566:Electrodes; D005625:Frontal Lobe / Q000502:physiology*; D051379:Mice
brain machine interface; intracortical microelectrode array; neural interface; neural recording; shape memory polymer