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Various methods are currently under development to enhance the biocompatibility of neural electrodes and to minimize the reactive gliosis around the implant surface. As cells in their native microenvironment interact with 3D nanoscale topographies of the extracellular matrix, physical modification of implant surfaces may provide an alternative solution to the negative tissue response by imitating the structure of the extracellular matrix, and therefore affecting the attachment and behavior of neurons and glial cells. The attachment of primary mouse astrocytes on nanostructured SU8 polymer surfaces fabricated by e-beam lithography was investigated in our study. We found that attachment of primary mouse astrocytes on silicon-SU8 surfaces is strongly influenced by the surface topography.

Utilization of polymers as insulator and bulk materials of microelectrode arrays (MEAs) makes the realization of flexible, biocompatible sensors possible, which are suitable for various neurophysiological experiments such as in vivo detection of local field potential changes on the surface of the neocortex or unit activities within the brain tissue. In this paper the microfabrication of a novel, all-flexible, polymer-based MEA is presented. The device consists of a three dimensional sensor configuration with an implantable depth electrode array and brain surface electrodes, allowing the recording of electrocorticographic (ECoG) signals with laminar ones, simultaneously. In vivo recordings were performed in anesthetized rat brain to test the functionality of the device under both acute and chronic conditions. The ECoG electrodes recorded slow-wave thalamocortical oscillations, while the implanted component provided high quality depth recordings. The implants remained viable for detecting action potentials of individual neurons for at least 15 weeks.

This study uses photoluminescence (PL) and other carrier-recombination sensitive probes in combination with spreading resistance profiling (SRP), SIMS and IMSIL MC-calculations to monitor the ion range and damage levels in highly-channeled and random beam orientation 7.5 MeV B and 10 MeV P and As profiles and various combinations of co-implants with 50 keV Phosphorus implants in Silicon(100). The effects of annealing on the 10 MeV profiles showed the strong shifts in PL data from implant damage in the as-implanted and annealed samples. Curious “intermittencies” were seen in the PL signals from MeV implant defect centers.