Since synapses are typically around 50 nanometres across, and each chemical puff contains just a few thousand molecules, building an artificial synapse is a huge challenge. But Mark Peterman and Harvey Fishman at Stanford University in California are getting close. They told a biophysics conference in Texas earlier in March that they have created four "artificial synapses" on a silicon chip one centimetre square.
To cells on the surface of the device, the artificial synapse is simply a hole in the silicon. But each hole opens into a pipeline etched into a plastic layer on the back of the chip, connected at both ends to a reservoir of neurotransmitter. When an electric field is applied, the neurotransmitter is pumped through the pipeline, and a little of it squeezes out of the hole, stimulating nearby cells.
[via Boing Boing Blog]