Micromachines (Jun 2020)

Mechanically Robust, Softening Shape Memory Polymer Probes for Intracortical Recording

  • Allison M. Stiller,
  • Joshua O. Usoro,
  • Jennifer Lawson,
  • Betsiti Araya,
  • María Alejandra González-González,
  • Vindhya R. Danda,
  • Walter E. Voit,
  • Bryan J. Black,
  • Joseph J. Pancrazio

DOI
https://doi.org/10.3390/mi11060619
Journal volume & issue
Vol. 11, no. 6
p. 619

Abstract

Read online

While intracortical microelectrode arrays (MEAs) may be useful in a variety of basic and clinical scenarios, their implementation is hindered by a variety of factors, many of which are related to the stiff material composition of the device. MEAs are often fabricated from high modulus materials such as silicon, leaving devices vulnerable to brittle fracture and thus complicating device fabrication and handling. For this reason, polymer-based devices are being heavily investigated; however, their implementation is often difficult due to mechanical instability that requires insertion aids during implantation. In this study, we design and fabricate intracortical MEAs from a shape memory polymer (SMP) substrate that remains stiff at room temperature but softens to 20 MPa after implantation, therefore allowing the device to be implanted without aids. We demonstrate chronic recordings and electrochemical measurements for 16 weeks in rat cortex and show that the devices are robust to physical deformation, therefore making them advantageous for surgical implementation.

Keywords