Neural recordings from a benzocyclobutene (BCB) based intra-cortical neural implant in an acute animal model

Multi-channel micro-electrode arrays provide unmatched spatio-temporal resolution for assessing the activity of populations of neurons. These neural implants provide a powerful tool for developing a better understanding of cortical processing, as well as provide an intimate interface for neuroprosthetic applications. Over the years, micro-wire based devices that are manufactured by hand, have allowed researchers to record for several months, and in rare cases up to a year or more. Devices based on microelectro-mechanical systems (MEMs) offer more controlled designs with the added benefit of batch fabrication. Polymer-based MEMs interfaces offer exciting promise over traditional silicon arrays due to their mechanical flexibility and excellent biocompatibility. In this paper we microfabricated a neural interface using a new class of polymer known as benzocyclobutene (BCB), developed for microelectronics under the trade name Cyclotene™. This polymer has properties that we believe make it an attractive candidate for chronic implant applications. We provide for the first time a quantitative assessment of its recording capability in an acute animal model. Continuous recordings of neural signals (100 μV) from barrel cortex of a rat were successfully demonstrated. These results are encouraging for further development of a long term implant based on BCB.