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Implantable Brain Interface: High-Density Microelectrode Array for Neural Recording

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Smart Sensors for Health and Environment Monitoring

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Abstract

During the past decades, the use of intracortical microelectrode arrays for brain–computer interface has increased due to the high spatial and temporal resolutions compared with the noninvasive methods such as electroencephalogram (EEG), functional magnetic resonance imaging (fMRI), and near-infrared spectroscopy (NIRS). Recently, it was also reported that the intracortical microelectrode was implanted to the human brain for the purpose of controlling a robot arm. Although the invasive method with the microelectrode may have the safety and the ethical issues, it is undoubtable that the microelectrode array can provide the most precise and effective means to directly record and modulate the neural activity. To date, a variety of multichannel microelectrodes penetrating mammalian nerve tissues have been proposed with respect to shapes, materials, fabrication methods, and so forth. Among the various types, the silicon-based microelectrodes array has gained the biggest technical advances as well as the clinical applications. Despite the large amount of advance in research, however, the clinical use of the intracortical microelectrode arrays has not been realized mostly due to the failure of functionality for long-term applications. It is believed that the major failure mode of the microelectrode arrays is the brain tissue reaction against the implanted electrodes. Since the glial encapsulation acts as an electrical insulation layer around the electrodes, the neuronal signals cannot be recorded via the electrodes. In order to overcome this problem, various strategies have been attempted including the electrode design optimization, the flexible microelectrodes and the drug delivery to suppress the tissue responses. In this chapter, the technical advances for the high-density microelectrode arrays are reviewed and the various strategies are discussed to enable the clinical use of the intracortical microelectrode arrays for brain–computer interface as well as the treatment of brain disorders.

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Acknowledgements

This work is supported by the Center for Integrated Smart Sensors funded by the Ministry of Science, ICT and Future Planning as the Global Frontier Project(CISS-2012M3A6A6054204) and the National Research Foundation of Korea (NRF) grant funded by the Korea government (MEST) (NRF-2014R1A2A2A09052449, 2014R1A1A1A05003770).

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Jun, S.B. (2015). Implantable Brain Interface: High-Density Microelectrode Array for Neural Recording. In: Kyung, CM. (eds) Smart Sensors for Health and Environment Monitoring. KAIST Research Series. Springer, Dordrecht. https://doi.org/10.1007/978-94-017-9981-2_4

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