We draw closer to merging mind and machine here
Looking a bit like the garbage-compacting hero of the blockbuster animation "Wall-E", Gordon has a brain composed of 50,000 to 100,000 active neurons.
Once removed from rat foetuses and disentangled from each other with an enzyme bath, the specialised nerve cells are laid out in a nutrient-rich medium across an eight-by-eight centimetre (five-by-five inch) array of 60 electrodes.
This "multi-electrode array" (MEA) serves as the interface between living tissue and machine, with the brain sending electrical impulses to drive the wheels of the robots, and receiving impulses delivered by sensors reacting to the environment.
Because the brain is living tissue, it must be housed in a special temperature-controlled unit -- it communicates with its "body" via a Bluetooth radio link.