Researchers at the University of Southern California Viterbi School of Engineering have developed thin, flexible polymer-based materials for use in microelectrode arrays that record activity more deeply in the brain and with more specific placement than ever before. What's more is that each microelectrode array is made up of eight "tines," each with eight microelectrodes which can record from a total 64 subregions of the brain at once.
In addition, the polymer-based material, called Parylene C, is less invasive and damaging to surrounding cells and tissue than previous microelectrode arrays comprised of silicon or microwires. However, the long and thin probes can easily buckle upon insertion, making it necessary to add a self-dissolving brace made up of polyethylene glycol (PEG) that shortens the array and prevents it from bending.
Professor Ellis Meng [usc.edu] of the USC Viterbi Department of Biomedical Engineering [usc.edu] and Michelson Center for Convergent Bioscience said that the performance of the new polymer-based material is on par with microwires in terms of recording fidelity and sensitivity. "The information that we can get out is equivalent, but the damage is much less," Meng said. "Polymers are gentler on the brain, and because of that, these devices get recordings of neuronal communication over long periods of time."
Acute in vivo testing of a conformal polymer microelectrode array for multi-region hippocampal recordings [iop.org] (DOI: 10.1088/1741-2552/aa9451) (DX [doi.org])