Multichannel electrophysiological sensors and stimulators—particularly those used to study the nervous system—are usually based on monolithic microelectrode arrays. However, the architecture of such arrays limits flexibility in electrode placement and scaling to a large number of nodes, especially across non-contiguous locations. Here we report wirelessly networked and powered electronic microchips that can autonomously perform neural sensing and electrical microstimulation. The microchips, which we term neurograins, have an ~1 GHz electromagnetic transcutaneous link to an external telecom hub, providing bidirectional communication and control at the individual device level. To illustrate the potential of the approach, we show that 48 neurograins can be individually addressed on a rat cortical surface and used for the acute recording of neural activity. Theoretical calculations and experimental measurements show that the link configuration could potentially be scaled to 770 neurograins using a customized time-division multiple access protocol.
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The dataset that supports the plots within this paper and other findings of this study are available in the Supplementary Information and from the corresponding author upon reasonable request.
Custom-developed MATLAB codes for demodulation are available in the Supplementary Information and from the corresponding author upon reasonable request.
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We thank Y.-K. Song for insights into microfabrication and ASIC design, J. Jeong for his expertise with neurograin hermetic sealing and materials processing, and R. Rao for guidance on wireless networking design. We also thank C. Kilfoyle, E. Mok, S. Sigurdsson, and the Animal Care facility at Brown University for their contributions. We also acknowledge S. Li, S. Yu, L. Cui, S. Alluri and M. Lokhandwala at UCSD for their work on ASIC design and benchtop test. We have greatly benefited from the insight of our colleagues across multiple fields from microelectronics to brain sciences and clinical neurology: J. Donoghue, B. Dutta, J. Groe, L. Hochberg, T. Sejnowsky, K. Shenoy and S. Cash, among others. This research was initially supported by Defense Advanced Research Projects Agency N66001-17-C-4013, with subsequent support from private gifts. The post-processing work benefited from the equipment funded by MRI award no. DMR-1827453.
The authors declare no competing interests.
Peer review information Nature Electronics thanks Nitish Thakor, Samantha Santacruz and Jonathan Viventi for their contribution to the peer review of this work.
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Lee, J., Leung, V., Lee, AH. et al. Neural recording and stimulation using wireless networks of microimplants. Nat Electron 4, 604–614 (2021). https://doi.org/10.1038/s41928-021-00631-8
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