electronics, proving the biocompatibility of the electronics. It is noticeable that the
width of ribbons was similar to the neurite projections, exhibiting seamless inte-
gration between them (Fig.5.14b).
Fig. 5.12 Control experiments of thinfilm electronics in needle.a(I, II), Optical image shows
5-mm-wide thinfilm electronics was injected through 400-μm inner diameter glass needle (I), and
1.5-mm-wide thinfilm electronics was injected through 350-μm inner diameter glass needle (II).
Red arrow indicates the direction of injection. White arrows in (I) indicate the end of metal line to
show the thinfilm cannot totally go through the needle.b(I, II), Top view of 3D reconstructed
confocal images correspond to dashed box in (a).c(I, II), Images at cross-section as indicated by
white dashed line in (b). White dashed circle in (c) highlights the needle boundary
86 5 Syringe Injectable Electronics