Fig 1

Carbon nanotubes modulate neuronal growth. (a) Fluorescence images of live neurons grown on PEI-coated coverslips and SWNT-PEG films of varying conductivity 28. Reprinted with permission from Ref.28, © American Chemical Society 2009. (b) Confocal micrographs of hippocampal cultures grown on 2D-PDMS control substrates and 3D-PDMS scaffolds 34. Scale bar: 100 μm. (c) Confocal reconstruction of a 3D-MWCNT scaffold (in grey), neurons (in red) and glia cells (in green) 34. Scale bar: 50 μm. Reprinted with permission from Ref.34, © Nature Publishing Group 2015."

Fig 2

Carbon nanotubes as conducting layers or coating layers of neural electrodes. (a) SEM images of pure CNTs probes 36. Scale bars: 1 μm. (b) Well-isolated single unit activities recorded from pure CNTs probes 36. Reprinted with permission from Ref.36, © Public Library of Science 2013. (c and d) Optical transparency of the CNTs electrode array and light-evoked potentials under photostimulus of different stimulus intensity and duration 41. Reprinted with permission from Ref.41, © American Chemical Society 2018. (e) Optical microscopy image of TiN microelectrode arrays printed by functionalized COOH-MWCNTs 46. (f) Waveform recorded by MWCNTs modified microelectrode 46. (g) The extracellular spikes amplitude detected by CNTs-coated MEA electrodes and uncoated electrodes 46. Reprinted with permission from Ref.46, © Wiley-VCH 2011."

Fig 3

Silicon nanowire-based nanoelectronic devices for neural interfaces. (a) Schematic of the probe with paired U-SiNWs FETs 58. (b) Simultaneous intracellular recording from one DRG neuron by two FETs on one probe arm (ⅰ); derivative of traces in the region marked by a dashed box (ⅱ) 58. Reprinted with permission from Ref.58, © Nature Publishing Group 2019. (c) Colorized angle-view SEM image of hiPSC-derived cortical neurons cultured on a Si nanowire array and measured potentials on channels 6–8 66. Scale bar: 4 μm. Reprinted with permission from Ref.66, © American Chemical Society 2017. (d) Schematic of the setup used to record DRG neuron action potentials in response to a 532 nm laser stimulation at a single neuron/SiNWs interface 71. (e) SEM images of the neuron/PIN-SiNWs interface 71. (f) Patch-clamp electrophysiology current-clamp trace of membrane voltage in a DRG neuron stimulated by injected current (blue pulse) and a laser pulse (green bar) 71. Reprinted with permission from Ref.71, © Nature Publishing Group 2018."

Fig 4

Graphene-based electronics for neural recordings. (a) Fluorescence images of hNSCs differentiated on glass and graphene 21. Scale bar: 200 μm. Reprinted with permission from Ref.21, © Wiley-VCH 2011. (b) SEM images of the tip of the Pt-coating graphene fiber microelectrode 77. Reprinted with permission from Ref.77, © Wiley-VCH 2019. (c) Tilt SEM image of a 64-spot porous graphene array 79. Scale bars: 1 mm and 100 μm. (d) Spontaneous up and down states recorded cross the 16-electrode array 79. Reprinted with permission from Ref. 79, © Nature Publishing Group 2016. (e and f) SEM image of a highly crumpled graphene/CNTs transistor and real-time recording of penicillin-induced epileptic activity in rats 84. Reprinted with permission from Ref. 84, © American Chemical Society 2016."

Fig 5

Graphene microelectrodes for multimodal neural interfaces. (a) Diagram of carbon-layered electrode array (CLEAR) construction 87. (b and c) Fluorescence image of CLEAR device (scale bar, 500 μm) and optical evoked potentials (x-scale bar, 50 ms; y-scale bar, 100 μV) 87. Reprinted with permission from Ref.87, © Nature Publishing Group 2014. (d) Three different types of graphene multielectrode arrays with varying electrode site diameters (100, 150, 200 μm) 88. (e and f) Visualization of the fluorescent neural response and the response intensity after electrical stimulation with graphene electrode 88. Reprinted with permission from Ref.88, © American Chemical Society 2017. (g) Bright-field image of an exposure with graphene microelectrode array. Scale bar: 500 μm. (h and i) Measurement of vascular responses to optogenetic photostimulation below graphene microelectrode arrays 90. Scale bar: 500 μm. Reprinted with permission from Ref.90, © Nature Publishing Group 2018."

Fig 6

Other 1D and 2D nanomaterials for neural interfaces. (a) The photograph and SEM image of electrode grids 96. Scale bars: 500 μm, 20 μm and 1 μm. (b) Raw LFP trace highlighting a spatially patterned gamma oscillation during an NREM epoch 96. Scale bar: 100 ms. Reprinted with permission from Ref.96, © Wiley-VCH 2018. (c) Illustration and SEM image of retina-nanowire interfaces 97. Scale bar: 5 μm. (d) Near UV, blue and green light responses in wild-type, blind and NW arrays-interfaced blind retinas 97. Reprinted with permission from Ref. 97, © Nature Publishing Group 2018. (e) Bright-field microscopy and SEM image of Ti3C2/Au intracortical electrode array 105. (f) Comparison of in vivo signal recorded on Ti3C2 and Au electrodes intracortically 105. Reprinted with permission from Ref. 105, © American Chemical Society 2018."