Recent advances in silicon-based neural microelectrodes and microsystems: a review

The aim of this review is to give an overview on various aspects of silicon-based implantable neural microelectrodes and microsystems developed in the last decade. Microfabrication approaches of 2-D and 3-D arrays are summarized. Features of the latest active microelectrodes including CMOS signal processing circuitry are compared. Integration methods of convection enhanced drug delivery functions for local administration of pharmacons are demonstrated. Performance of recent silicon-based chemical sensors for the detection of neurotransmitters is also studied. An analysis on the latest developments in silicon-based optrodes for optogenetic and thermogenetic stimulation is also included in this paper. Microelectrode-tissue interaction is described through the evaluation of recent experimental studies on in vitro and in vivo biocompatibility.