Fig 1

In vivo neural interface and historic roadmap of DARPA neurotechnology. (A) Neural interface electrode types and neural oscillation frequency band functions (ECoG, Electrocorticography; EEG, Electroencephalogram); (B) Historic roadmap of DARPA neurotechnology projects. "

Fig 2

MEMS (Micro-Electro-Mechanical Systems) fabricated electrode arrays and devices. (A) High density grid ECoG recording electrode array 40c; (B) High-density polymer electrode array 48; (C) Recording setup of 1024 channel polymer array 48; (D) Microfluid and electrophysiology electrode array 55; (E) Neurotassl electrode array (PEG, Polyethylene glycol) 36; (F) Multi-functional fiber 54; (G) Neuropixel electrode array 28; (H) Ultraflexible high-density electrode array 33; (I) Cross-section of multi-functional fiber device (PC, Polycarbonate; COC, cyclic olefin copolymer; gCPE, graphite-conductive polyethylene) 54; (J) SEM(Scanning Electron Microscopy) of neuropixel electrode 28; (K) Transparent stretchable electrode array 43; (L) Retina implantable electrode array 44; (M) Neuron-like electrode array 34; (N) Stretchable electrode array 43. (A, B, C) Reprinted with permission from Elsevier. (D) Reprinted with permission from Royal Society of Chemistry. (E, L) Reprinted with permission from The American Association for the Advancement of Science. (F, G, I, J, M) Reprinted with permission from Springer Nature. (H) Reprinted with permission from John Wiley and Sons. (N, K) Reprinted with permission from American Chemical Society. "

Fig 3

Application of nanomaterial and nanodevices in neural recording and stimulation. (A) Membrane electrode with nanopillars 72; (B) SEM of nanopillar device 91; (C) Optical modulation of cellular activity with SiNW (silicon nanowire) 74; (D) Optical modulation of neurons with silicon nanowire 75; (E) SEM of ultrasoft nanowire electrodes 49a; (F) Nanoparticle to enable infrared vision in mice (UCNP, Upconversion Nanoparticles) 80; (G) Interface of ultrasoft electrode with cardiomyocytes 49a; (H) Subcellular interface nanopillar device 85; (I) Nanowire arrays to restore vision in blind mice 80. (A, C, H) Reprinted with permission from American Chemical Society. (B, D, (E), G, I) Reprinted with permission from Springer Nature. (F) Reprinted with permission from Elsevier. "

Fig 4

Wireless neural interface devices. (A) Nano-transistor device for wireless energy harvest 81; (B) Neural dust wireless device 82; (C) FET (Field Effect Transistor) device with Bacteriorhodopsin 83; (D) Neural dust device system 82; (E) Fully resorbable stimulation device 69; (F) Optogenetics device 84; (G) SEM of wireless optogenetics device (μ-ILEDs microscale, Inorganic Light-Emitting Diodes) 84. (A, E) Reprinted with permission from Springer Nature. (B, D) Reprinted with permission from Elsevier. (C) Reprinted with permission from John Wiley and Sons. (F, G) Reprinted with permission from The American Association for the Advancement of Science. "