Mechanically Adaptive Silicon-based Neural Probes for Chronic High-resolution Neural Recording

A hybridly assembled, neural probe based on silicon (Si) with reduced dimensions and improved mechanical flexibility is proposed as a chronic neural interface. In contrast to previous approaches, the microelectrode array at the probe tip will be completely implanted into cortical tissue and tethered only by a slender and highly flexible, 11-mu m-thick polyimide cable. The Si-based electrode arrays carry 16 or 32 channels and feature cross-sections as small as 50 x 120 mu m(2) across their entire length. Implantation of the flexible probes is facilitated by a temporary increase in probe stiffness using a bio-dissolvable polymer coating. The centrifuge-based molding of polyethylene glycol creates sharp insertion vehicles with a thickness of only 75 mu m. Probe implantation up to 9 mm into agar-based brain models demonstrates the insertion capability of the novel mechanically adaptive neural probes. (C) 2015 The Authors. Published by Elsevier Ltd.