Scientists have engineered flexible electronics that can be injected into brain tissue through a needle to mesh with biological brain cells.

This mesh of electrodes can unfold once in position and has so far been used to monitor brain activity in mice.

This suggests it may be capable of similar feats in humans one day. Ray Kurzweil, Director of Engineering at Google said in 2013 that it will also be possible to replace body parts with mechanical devices and that this could happen by the end of the century. […]

related reading:
Royal Society of Chemistry — Chemistry World | Injectable electronics unfold to monitor brain activity
Harvard University — Harvard Gazette | Injectable device delivers nano-view of the brain