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
(about 50-100 nm in size) 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.