Dual-mode Microelectrode Array with 20k-electrodes and High SNR for High-Throughput Extracellular Recording and Stimulation

Abstract

Event Abstract Back to Event Dual-mode Microelectrode Array with 20k-electrodes and High SNR for High-Throughput Extracellular Recording and Stimulation Xinyue Yuan1*, Andreas Hierlemann1 and Urs Frey1, 2 1 ETH Zürich, Department of Biosystems Science and Engineering, Switzerland 2 MaxWell Biosystems, Switzerland Motivation Recording and analysis of neuronal signals can provide much insight into how neurons process information and communicate with each other. Recent advancements of microelectrode-array (MEA) technology provide unprecedented means to study neuronal signals and network behavior in in vitro and in vivo applications [1], [2]. The trade-off between noise performance, power consumption and electrode density, however, remains a major challenge in MEA design. To balance this tradeoff, we designed a Dual-mode (DM) MEA that combines two major types of readout schemes, i.e., the active-pixel-sensor (APS) and switch-matrix (SM) schemes, in order to achieve high electrode density and high signal-to-noise ratio (SNR) at the same time. Based on a previous prototype [3], the new DM-MEA has shown to be a useful tool for in-vitro neuroscience studies, especially for network studies. Material and Methods The DM-MEA consists of 108 x 192 pixels with a pixel size of 16.8 x 18.2 µm in a hexagonal arrangement [4], resulting in a total of 19,584 electrodes at an electrode pitch of 18.0 µm. The system includes 19,584 APS readout channels, 246 SM readout channels and 8 stimulation buffers. Every electrode can be simultaneously read out in APS and SM mode and can be used for electrical stimulation through voltage or current stimuli. Results The DM-MEA has been fabricated using 0.18 µm CMOS technology. The chip size is 9.0 x 6.0 mm2 with an array size of 2.0 x 3.6 mm2. The noise level, estimated from simulations was 10.4 µVrms for the APS mode and 2.4 µVrms for the SM mode in the action-potential frequency band (300 Hz – 5 kHz), and the total estimated power consumption was 96.8 mW. Currently, we are working on the electrical characterization and initial biological measurements of this DM-MEA. Conclusion Compared to single-mode MEAs (APS or SM), the DM-MEA features more options for recording extracellular action potentials of a wide range of preparations and is particularly suited for studying large neuronal colonies and networks. Acknowledgements Financial support through the European Research Council Advanced Grant 694829 ‘neuroXscales’ is acknowledged.