Switchless Multiplexing of Graphene Active Sensor Arrays for Brain Mapping.
Nano Lett. 2020 Mar 30. doi: 10.1021/acs.nanolett.0c00467. [Epub ahead of print]
|Authors/Editors:||Garcia-Cortadella R, Schäfer N, Cisneros-Fernandez J, Re L, Illa X, Schwesig G, Moya A, Santiago S, Guirado G, Villa R, Sirota A, Serra-Graells F, Garrido JA, Guimerà-Brunet A.|
Sensor arrays used to detect electrophysiological signals from the brain are of major importance in neuroscience and biomedical engineering. However, the number of sensors that can be interfaced with macroscopic data acquisition systems currently limits the bandwidth of these devices. This bottleneck originates in the fact that, typically, sensors are addressed individually, requiring a connection for each of them. Herein, we present the concept of frequency-division multiplexing (FDM) of neural signals by graphene active sensors. We demonstrate the high performance of graphene transistors as mixers to perform amplitude modulation (AM) of neural signals in-situ, which is used to transmit multiple signals through a shared metal line. This technology eliminates the need for switches, remarkably simplifying the technical complexity of state-of-the-art multiplexed neural probes. Besides, the scalability of FDM graphene neural probes has been thoroughly evaluated and their sensitivity demonstrated in-vivo. Using this technology, we envision the implementation of a new generation of conformal neural probes with over a thousand channels for high bandwidth brain machine interfaces.