The biological elements are typically rat neurons connected to a computer chip.
This feat was first accomplished in 2003 by Dr. Steve M. Potter, a professor of biomedical engineering at the Georgia Institute of Technology: In his experiment, Potter places a droplet of solution containing thousands of rat neuron cells onto a silicon chip that's embedded with 60 electrodes connected to an amplifier.
Equipped with light sensors, the robot receives input about its location in the playpen from infrared signals lining the borders.
Neurons separated from a living brain usually die after only a couple of months.
However, a specially designed incubator built around a gas-tight culture chamber selectively permeable to carbon dioxide, but impermeable to water vapor, reduces the risk of contamination and evaporation, and may extend the life of the hybrot to one to two years.