the invention provides microfabricated devices and methods for directing the growth of a cell process to form an artificial synapse . the devices are called artificial synapse chips . the artificial synapse comprises a nanofabricated aperture that connects the cell process to a chemical or electrical means of neuronal excitation . such an aperture width mimics the length scales of a natural synapse and thus emphasizes the localized spatial relationship between a neuron and a stimulation source . the invention further provides devices and methods for regenerating a nerve fiber into an electrode . the invention thus provides a regeneration electrode that uses a novel neural interface for stimulation and that uses novel surface methods for directing neuronal growth making possible in vivo connection of the devices to neural circuitry in a retina and other anatomical locations .