Fig. 7: Implantation precision assessed in vivo.

A single-layer ensemble of planar silicon chiplets and a multilayer ensemble of glass microspheres were acutely implanted into the rat cortex and imaged by a micro-CT scanner. a The experimental setup is displayed with the insertion device as well as the implantation tool above the target cortical location prior to implantation. The arrow indicates the exposed craniotomy. b Reconstruction of an intracortical 6 × 6 array 3D distribution of ~260 glass microspheres, viewed at an angle. c Reconstructions of two single-layer 6 × 6 array distributions of planar silicon chiplets displayed from a top view, one implanted into agarose and the other into the rat cortex. Some chiplets that have rotated towards a 90° tilt are circled in red. d and e Outcomes of the experiments in c were quantified. d Histogram showing the horizontal displacement of particles (20 µm bin size) from their respective vertical implantation columns (center-to-center) in agarose and in rat cortex. e Histogram showing the deviation of particles in terms of tilt in orientation (10° bin size) from the initial horizontal orientation in agarose and in rat cortex. Note the near uniform distribution of particle orientations in the rat cortex. Scale bars in b and c measure 500 µm