Fig. 5.15 Injectable electronics for brain implants.aSchematic shows stereotactic injection of
injectable electronics into in vivo system.bOptical image shows the stereotactic injection of
injectable electronics into mice brain tissue.cSchematics of coronal slices show that injectable
electronics are injected into cerebral cortex (CTX) and hippocampus (HIP) region of brain (I), and
the cavity of Lateral Ventricle (LV) beside caudoputamen region (CPu) and lateral septal nucleus
(LSD) with unfolding (II). Red: mesh structure of injectable electronics, blue: nanodevices or
metal electrodes on injectable electronics and yellow: I/O pads for electrical connections. Blue
dashed lines indicate direction of horizontal slicing for imaging.dBright-field image of coronal
slice in (c, I) shows the electronics was injected into the cortex and hippocampus region. Red
dashed lines indicate the boundary of glass needle.eOverlaid brightfield and epi-fluorescence
image of white dashed box highlighted region in (d). Blue: DAPI. White arrows indicate the
different layers of cells in hippocampus. GrDG: granular layer dentate gyrus and CA3:field CA3
of hippocampus.fProjection of 30μm thick volume from the zoomed-in region by black dashed
box in (e) shows neural cells interface with electronics.gProjection of 100μm thick volume for
the electronics injected into LV inside brain at the position indicated by blue dashed line in (c, II).
Red dashed line highlights the boundary of unfolded mesh inside LV. Red circle indicates the size
of the needle for injection.h3D render of the zoomed-in region highlighted by white dashed box
in (g) shows the interface between nanoelectronics and subventricular zone.i3D render of the
zoomed-in region highlighted by white box in (g)
5.3 Results and Discussion 89